My understanding of the political science research on this topic was that political polarization post-Internet was mostly a USA-specific thing, and you did not see as strong a polarization elsewhere when you take a systematic look.
(It wouldn't be surprising if people base their impressions "politics is so polarized these days" solely on the one example of the USA and are badly wrong about their generalization, because due to media and the Internet especially, everyone pays a ton of attention to American politics, whether or not they want to, and typically ignore other countries. For example, Japanese politics - out of the ~200 countries worldwide, Japan is one of the most important countries, a member of G8, fourth-largest economy etc - but can you name the current PM - not the ex-PM who was assassinated 2 weeks ago, assuming you remember that at all, but the current PM? I doubt it. I thought I did but then I checked and I was remembering the previous one, Suga. Now, can you tell me if Japanese politics is more or less 'polarized' in 2022 than it was in 2012? Personally, I don't have a clue.)
So, since it's US-specific and changes over time, most of these hypotheses aren't even wrong because they are explaining observations which don't exist. In countries with extensive public funding for campaigns, how can changes in 'donating' happen, much less drive the polarization which also didn't happen? (Not that money matters remotely as much as people think in the first place, and is mostly a reverse causality deal: victors raise money, money doesn't raise victors. Ask Bloomberg how easy it is to buy a vote.) And they also don't explain why it would increase when they are levels: politicians have always been irrational, why would they be moreso now? That's what would then need to be explained, otherwise it's just passing the buck.
I take some of those points. I don't know the state or trend of polarization in other countries (only countries with two main parties would be of interest for this model, multi-party elections yield a different system). Though I maintain that one country is still an observation to be explained, requiring a hypothesis. I could also believe that donations or activism don't drive election performance.
But fundamentally, I think you're addressing an issue with my suboptimal framing of the puzzle, rather than the puzzle itself. I'm not really interested in the time trend (increase?) of the polarization of politicians. From the perspective of MVT, it's surprising that there are any differences between the two main candidates' positions, irrespective of the amount of polarization in the electorate. Certainly it's surprising that when elections are close, politicians don't move further towards the center in order to win - something must be restraining them. What is it?
I agree individual politicians could be irrational (in the sense of not optimizing for getting elected, though the precise mechanism still interests me). For example, maybe they do not change their true ideological positions to appeal to voters even when getting elected is at stake (is this likely?). But you'd still need to explain why other politicians, whose views are genuinely more moderate, don't emerge and win the elections. In the same way that individual producers and customers could be biased/selfish, but the market could still end up efficient & useful, the political system could have generated the most electable politician, who is a moderate. Why doesn't it? I can't think of any hypothesis not listed or raised so far.
This is decidedly not what we see in the US (or in any country) - the two parties’ views differ substantially.
The views of the parties differ substantially on some issues but not on others. It's quite natural that most of the focus of the public debate is on differences and not on what's the same.
A recent post on LessWrong wrote:
Certain studies emphasize partisan differences, but most find that the ideology of governing parties has indiscernible to small influence on policy, one meta-analysis establishing that the ‘average correlation between the party composition of government and policy outputs is not significantly different from zero’.
George Bush campaigned on "No national building" and went to start the wars in Afghanistan and Iraq which were massive nation-building projects.
That's interesting. I agree I glossed over many (most) parts where the parties agree (on general democratic principles, on capitalism in some form, on the order of magnitude of budget for many things) and focused on issues where they disagree.
But I think for my thesis, any remaining differences are a puzzle to be explained, and the perceptions that the parties differ is what drives the results. Since public debate focuses on issues where parties differ substantially, these should be the issues driving voting behavior - you can narrow down the model to those issues and still try to explain the puzzle, right? If voters don't perceive a difference between the parties, what is driving the changes in voting between different election cycles?
I upvoted this post - it is a good stab based on the easily accessible public information and a look at relevant theory.
Hypothesis 5 is the path to victory here. The core problem is that (almost) everyone is wrong about (almost) everything, and the least wrong people do not form a group. Some examples:
Moderates do not exist. By this I mean there is not and never was any such group of people. The existence of moderates is a mistake in tabulating the results of political surveys. The mistake looks like this: you might have a survey with multiple responses, and one person responds:
Q1. How do you feel about gay marriage?
A1. Gay people should have civil unions rather than marriage
Q2. How involved should the government be in the economy?
A2. Government should keep taxes low
But another person responds with:
Q1. How do you feel about gay marriage?
A1. Gay people should not be allowed to get married, or adopt, or teach children
Q2. How involved should the government be in the economy?
A2. Government should heavily tax the rich and important industries should be nationalized
Since both answers for the first person were conservative, the surveys marked that person as "very conservative." The second person, with one extremely conservative answer and one extremely liberal answer, got marked as a moderate. It turns out if you graph the policy preferences of people who are moderate, undecided, or independent, they land all over the ideological map.
But most politicians, pundits, campaign staffers, and voters believe in moderates.
Money does not win elections. The narrative is straightforward here: the side with the most money usually wins, so money most be what caused victory. The best natural experiments for this are repeated contests between the same two people, and when we look at these contests we find that the effects of money are very weak: the number I remember is doubling the money brought 1% more of the vote and halving it cost 1%.
The alternative explanation based on this is the more likable/popular candidate receives more political donations. This one passes the smell test: if we invert these stories, it would be very weird if the actually-more-popular candidate systematically got less money, and it would be wild if the person who got more money systematically lost the election.
But most politicians, pundits, campaign staffers, and voters believe money wins elections.
Americans are not politically engaged. This one is something that campaign people understand, but the other groups mostly ignore in practice: a huge chunk eligible voters don't vote. Campaigns target the populations that do vote, and policy is heavily influence by what is popular in campaigns.
The key insight here is that both parties in the US tend to enforce this rather than try to expand the electorate. While the blue team is notionally friendlier to this idea than the red team, what they do in practice is try to increase the participation rate of groups which they already expect to support them. This is why voter turnout is the conversation: the default election strategy is to identify the groups of likely voters and that are likely to support your side, then try to get the number of them that show up on election day as close to 100% as possible. At the same time, it is common to try and reduce voter turnout for the opponent. This is the mechanism of negative advertising - it drives people to stay home and not vote at all.
But most politicians, pundits, and voters believe campaigns are trying to persuade the public to vote for them instead of the other person. This is similar to the mechanism of the primaries hypothesis above, but primaries are explicit to party membership and activity.
Some issues are more relevant than others. The word political scientists use for this is salience. In elections, no candidate is ever evaluated by the public on the basis of all of their positions; instead, there are usually a few issues the election becomes "about", and the candidates which are better positioned on those issues tend to win (subject to the turnout considerations above). This one also passes the smell test - even the smallest elections encompass a wide range of issues, and I definitely expect attention bandwidth to be a limiting factor.
This is why messaging is so important - if a side can keep messaging discipline, then what the message is about is more likely to be what the election is about. I think this is also what drives a lot of those "X is really about Y" style arguments - these look to me like bids to increase the salience of one issue at the expense of another.
But, most politicians, pundits, and campaign staffers tend to act like the stuff they care about should be the issues of the campaign. This is much like your echo chamber hypothesis above.
All of this is compounded by all the usual problems like how difficult social research is, statistical incompetence, professional biases, etc.
In summary, I feel like the true model is a model of everyone else's models being borked.
Not sure this is a good use of the MVT but I came to the view long ago that MTV is a really bad model for general voting and elections but is a good model for party formation and platform - and I suppose, therefore, primary voting. I think as you start collapsing the complex issue space into a common dimension as it typically illustrated one should expect to see a multi-modal distribution. The modal centers then become the party platform locus.
I very much agree this is possible, if voters vote in primaries based on ideological proximity rather than electability. But then how come the national elections are close? Coincidence? And what would happen if a politician moved a bit more towards the center after winning the primaries?
A bit late seeing this. And I don't think I have answers but a couple of thoughts on your questions.
I don't think it's coincidence but more like party affiliation have similar population sizes and similar voting participation rates then outcomes will likely be very close even when party platforms are far apart.
If the primary process pushes each side farther apart then any post primary move towards the center will only get shifts form those in the tail of the "other side" they want to steel votes from while probably alienating voters from a fatter section of the distribution they represent. So that is a p1*n1 = new votes taken from center and p2*n2 = votes lost from other half of your support distribution. I suspect p1 might be fairly high but n1 is very low while p2 is low (not sure how low to guess at) while n2 is probably much larger than n1. (This said, I do think you not only have generally seen that "move towards the center" in many elections as well as while in office. But seems to me this has not been happening in the more recent elections where are seeing party platforms much farther apart than say the past 40-50 years.)
Alternate theory: virtue signaling over policy preference. Voters mostly don't care about the details, only about showing their family and peers that they're part of the tribe, and have the "correct" passion about politics.
This leads to one-upsmanship of extreme ideas, and acceptance that supporting this is the way to belong. This is how voters get polarized. And this style of polarization means they hate moderates (because they weaken the tribe), so politicians don't succeed unless they are at least as polar as their base.
Interesting. And how do you think they enforce this dislike of moderates? By not voting at all? By voting for the other party if it's more extreme? If they prefer extreme politicians but still vote for the politician closest to their views, the puzzle isn't solved.
The obvious thing to keep in mind is that people dislike 'inauthentic' politicians but there are many things the people want in politicians. If a politician wants to portray a certain image to match what people like, they have to pick the policy positions that go along with it to avoid said label. Said images are not so evenly or finely distributed as policy positions, so that tends to lead to significant differences along these axes.
Then, over time, the parties accrete their own new images too, and people have to position themselves in relation to those too...
Interesting topic! My political science capstone course covered some of these questions, so I ended up writing about/researching these concerns pretty frequently. Basically, the main explanation points out that recent politicians have been campaigning on moral grounds at increasingly alarming rates. They frame their opponents as not only less informed/less fit to hold office than themselves, but portray rivals as legitimate dangers to the country. By assigning positive moral value to their own platforms and negative moral value to the ideas of their opponents, they intensify polarization by convincing voters that compromises/middle ground positions are unthinkable. If a member of the opposing party isn't merely someone with a differing opinion about immigration, for example, but a representation of a perverted philosophy, it follows that voters wouldn't want to elect politicians that are open to collaborating with them or engaging in meaningful conversation with them. Moderate candidates are consequently viewed as unreliable figures that compromise their beliefs.
Unfortunately, this attitude affects local and state level politicians as well as voters. Politicians well outside the D.C. sphere pledge their support for Trump, for example, to align themselves with a broader ideological movement. In turn, Republicans that might not agree with Trump's unprecedented behavior feel pressured to include pro-Trump messages in their advertisements and speeches in order to secure votes (regardless of whether they actually approve of Trump's actions). This prominent type of polarization results in more extreme ideological differences than we've seen in earlier decades.
Sadly, this wave of polarization also lends itself to the two major parties essentially operating in different realities. We've observed politicians promote bizarre conspiracies (MTG) and openly distrust reliable information because it's presented by members of an opposing faction. Furthermore, the religious element present in many campaigns (especially those of Republicans) presents an additional challenge as candidates aligned with faith-based beliefs often receive a semblance of immunity from their bases.
This is an interesting explanation. But then how do you think voters enforce their views to make politicians more radical? Suppose there were general elections between two candidates, and then a voter's preferred candidate made his views more moderate to appeal to a larger audience. Would the voter not vote at all in these elections? Or would that politician just not pass the primaries? Otherwise, even if voters dislike it, a politician could still get elected while being less liked than they could have been by their party's voters, but importantly - win the elections.
I'm basically a "moderate," I don't like tax cuts for the rich and am angry about Dobbs. But I won't be voting for a group of people who gleefully advocate firing me from my job because I don't support transgenderism and MeToo. I'll probably sit out the midterm elections
I think it's wishful thinking. People respond better to "I'll give you 100% of what you want" than "I'll give you 66% of what you want." Joe Manchin isn't in the echo chamber and has proven he can win a state Democrats normally write off. But there's far more support for "kick Joe Manchin out of the party" than "make Joe Manchin our standard-bearer."
I think when you look at level remaining support for truly disastrously unpopular governments, it seems about 50-60% of population view politics as tribal and would vote for their tribe no matter who the candidate is or what the policy statement. Furthermore, voters are likely to vote for party rather than candidate because you only get your preferred policies if you your party wins. Of the remainder, a substantial proportion are still tribal and would only vote for the opposition rarely in cases where fed up. ("death of a thousand cuts"). Truly swinging voters probably have a disproportionate influence on elections. As an outsider looking in on USA, it seems to me that polarization is being driven by a balkanized media (people can effectively choose a "reality" from their news sources). These can fan tribalism (it is in the media interest) using the traditional tribal identities of race, religion and class. Excessive power given to president compared to congress bypasses the ameliorating influences that parliamentary systems possess. The voting system in USA also makes it extremely hard for other parties to attract any votes so the art of compromise necessary in proportional systems is missing (and indeed despised).
Not sure I understand how this explains the polarization of politicians. What is preventing Biden from saying "Abortion is a state issue"? His tribe will still support him, but some fraction of the swing voters will find him more appealing. Couldn't it sway the elections in his favor? Why didn't he do it? Generally I don't see how tribalism is a challenge to the thesis.
Again, as an outsider, I scratch my head over the behavior of the US politicians themselves. It seems more centrist positions would indeed bolster election chances, but instead politicians play to their bases and I dont think that helped Trump nor is it helping Biden. Despise of compromise? Or that playing to the base is necessary for winning the primary and you cant retreat? I find your hypothesis 4 pretty compelling.
I think elections are generally close because successful parties have evolved to find electable platforms. If you always lost, you would change your platform to become more electable. (Look at the rise the "Labour" parties in countries like UK, Australia and NZ as they gradually lost extreme positions. Similar things are happening in Green movements).
When looking at polarization in the US, it's more at the Congressional level than at the presidential level and this is often due non-competitive general elections so the winner of the primary will be the winner of the general election. This has gotten worse as gerrymandering has continued to increase. In more competitive races, you see the political parties trying to select more moderate candidates.
[party elites, politicians and donors] have much more radical views than the median voter of their party
This is quite false. The median conservative wants gay marriage made illegal, abortion banned, significantly lower taxes, and does not care about human production of CO2. The median liberal wants men competing in women's sports, at-will abortion up until birth, wealth re-distribution, and global reductions in CO2 emissions. Yet these views are reflected in few of either party's senators and congressmen. I wouldn't take Yglesias's word on how radical politicians are given most all of what he writes is democratic propaganda.
Really? I am pretty horrified if either of those describe "median" positions. Doesnt seem to fit with eg:
https://www.pewresearch.org/science/2020/06/23/two-thirds-of-americans-think-government-should-do-more-on-climate/
https://www.forbes.com/sites/alisondurkee/2021/06/25/majority-of-americans-support-abortion-poll-finds---but-not-later-in-the-pregnancy/?sh=bfbc45b50744
https://news.gallup.com/poll/350486/record-high-support-same-sex-marriage.aspx
I find that your first two articles support my position as stated. 22% of republicans believe human activity is contributing a great deal to climate change, and 89% of democrats think the government is doing too little to stop climate change while only 35% of republicans agree. I for the life of me can't figure out how that jives with the specific questions about extra efforts the government could do, but whatever (if only 35% think the government is doing too little, how could 88% think the government needs to do more??) .
With the abortion article, you should look at the actual pollster's highlights and not the poorly formatted forbes highlights. https://apnorc.org/projects/public-holds-nuanced-views-about-access-to-legal-abortion/. 64% of republicans believe abortion should be illegal in most or all cases. 76!!% of democrats think it should be legal in all or most cases. This is a massive contrast and the median for each group lies in the "most" group skewed towards the "all" category.
And these polls are just for people who identify as republican and democrat. Please read my original comment which said 'conservative' and 'liberal.' If you want to be horrified, be horrified.
In the first poll, I see Republican support for specific measure to reduce CO2 range from 55%-88%. Since the questions deal with specifics, I think they avoid the tribal response and reflect true beliefs as opposed to "belief about beliefs".
On abortion, I agree that median democrats believes abortion should be legal in all cases, but NOT "up until birth" (low support for trimester).
I would agree that gap between conservative and liberal is large (and where I think a balkanized media is exacerbating the difference). I agree with original statement that many politicians have less radical (in public) views than the median voter because you need attract swing voters to win an election. Hardline politicians can only win in hardline electorates (but gerrymandering can help).
There has been a lot of attention dedicated to increased political polarization. And a lot of it has focused on the factors causing voters to be more polarized. I want to discuss a different, but related question. Given that voters have become more polarized, why are politicians more polarized? At first blush, you’d think this follows inevitably from the preferences of voters. Politicians try to position themselves around the central view of their voters, so if voters are more polarized, so will be the politicians’ views, right? Not necessarily. Let’s see why.
The puzzle: politicians’ polarization
Let’s describe this in a schematic (modeled on the US general elections), where we assume there are only two political candidates and that political views can be described as a single continuum[1] going from left to right, with each voter voting for the candidate which is closer to their position, and the candidate who gets more votes wins. You can imagine it might look like this:
This seems reasonable, until you consider what would happen if one of the candidates (or parties) decided to make their views more moderate. This could take the form of e.g. adopting one of the policies favored by the other party and less favored by the candidate’s party, to appeal to moderates (e.g. a Democratic candidate declaring that they do not intend to pursue any further gun control measures). They would move closer to the center, and grab the votes of the more moderate voters from the other side, and always win by a wide margin.
The other candidate would have to respond by moving closer to the middle as well, and then the original candidate would become more moderate still, until they converge to the median voter. This is how the Median Voter Theorem works. So even in the case of a highly polarized populace, it still predicts that candidates will be very moderate, with almost identical views.
This is decidedly not what we see in the US (or in any country) - the two parties’ views differ substantially. They might have even become more polarized recently. So something else must be going on. What could it be?
Hypothesis 1: Irrational Politicians, or “the echo chamber”
In our simplified model, we’ve been assuming that politicians position themselves optimally to garner the most votes, but maybe they are not rational, or don’t know which position will get them the most votes. The echo chamber hypothesis is that party elites, politicians and donors (who have much more radical views than the median voter of their party) hang out with one another in an echo chamber, and mistake their preferred policies for everyone's favorites, and so adopt and support them, not noticing that it takes away votes. This is the point Matt Yglesias and others constantly make on Slow Boring about Democrats.
If this were true, though, you might expect another candidate to pop up who is not affected by the echo chamber, or is naturally more moderate in his or her views, adopt more moderate views, be extremely popular and be overwhelmingly likely to win the elections against the other party. Wouldn’t people realize this and select this candidate to represent their party?
Hypothesis 2: Radical voters not voting for a moderate-but-preferred candidate
So far we’ve been assuming that all voters vote for the candidate who is closer to their views, irrespective of how close they are in absolute terms (this would make sense - after all, that candidate is still preferable to the other candidate). However, suppose that at some point, when the two main candidates are too far from your radical position, you vote for neither (instead of voting for the lesser evil, you vote for a third candidate or abstain entirely). Maybe you’re angry at both candidates and want to punish them. Maybe from such a great ideological distance they seem the same to you, and you can’t get emotional enough about voting to spend the time. So in the end you don’t vote. Here’s what this would look like schematically.
As you can see, by moving towards the center, the left candidate might lose more radical votes than win moderate votes. In that case, it stops being always optimal for the candidates to move closer to the median voter, and instead they also have to get closer to the radicals to get their votes. This is known as “appealing to the base”. It doesn’t even have to really be the case that radicals won’t vote - it’s enough for the politicians to think this is the case in order for them to adapt to it. Why would they think that? Maybe because of the “echo chamber”?
Interestingly, this means that from a game-theoretic perspective threatening not to vote could be a better rational strategy for radicals themselves, if they want to affect candidates' policy and not just leave all the influence to the median voter. But is it realistic? I’m sure there are some Bernie Sanders supporters who did not vote for Hillary Clinton in the general elections (or at least said they would, and maybe even did it if nothing was at stake). And there are some hard-core communists for whom both candidates are capitalist and nationalist and are barely distinguishable. But are they enough to sway the elections? I don’t have data on this, but I’m skeptical. If they’re not very numerous, then they’re not a good reason for candidates to change their positions, certainly not so drastically.
Hypothesis 3: Radical voters not donating or becoming activists for a moderate-but-preferred candidate
This is a variation on the previous hypothesis. I’m not convinced that radical voters will actually not vote in large numbers, but I find it much more credible that they won’t donate and will not become activists for candidates which are too far from their views. Imagine you’re a Democrat and the general elections are between Mitt Romney and Donald Trump. You have a preference, and if you could vote you probably would (because what else will you do with your vote). But would you donate to your preferred candidate? I think it’s far less likely (because there is a lot else you can do with your donation). Will you become an activist for your preferred candidate? Maybe even less likely.
In fact, we have a test for this. Democrats are free to donate to their preferred candidate in the Republican primaries, but I think almost none do. And I’m pretty sure none become activists for their preferred candidate in the other party’s primaries. True, there’s a possibility that your donation will be wasted because your party will win the general elections. But there’s also a possibility that the same amount of donation/activism will sway the chances of the candidate much more in the primaries than in the generals, so not sure how this balances out.
To the extent that donations and activism are important resources in winning the elections, and that they are really reduced when the candidate’s views are too moderate, they could make it rational for candidates to become more polarized in response to the electorate. Or rather in response to the donating / activist group, who could be even more polarized than the general public.
Hypothesis 4: Primaries
We glossed over how candidates are selected within each party, and assumed there is a single candidate from each party with the liberty to select their position optimally. But that’s not how it works, at least in the US. You have to become the party’s candidate. This happens through primaries. Suppose that in the primaries there are also only two candidates, that only voters of that party vote, and each one votes for the candidate closest to their position. In this case, the Median Voter Theorem applies in the primaries and forces the candidates towards the Median Voter of their party, who is far from the overall median voter. If voters in the primaries are more extreme in their views than the general party voters, their median will be even more radical.
Importantly, this requires voters in the primaries to vote for the candidate closest to their positions, without taking into account “electability” - the chances of the candidate winning the general elections. Electability is a crucial consideration if the goal of voters is to get their preferred policies implemented, for which they have to win the general elections.
But then why doesn’t the chosen candidate change their positions before the general elections, in order to get more votes by moderates and win? To some extent candidates do, but mostly they don’t abandon all the policies they advocated in the primaries. That would be viewed as “flip flopping”, reducing their credibility, and punished by voters. This yields a slightly different model for voters’ selection criteria, not based only on policy positions, but incorporating other factors such as desirable character traits - preferring a candidate who is brave, honest, competent and not corrupt.
OK, then it could be primaries at fault. But that still leaves a mystery - why are the general elections so close? How come there is drama on election day, and a percentage point or two in each direction could sway the result? Primaries don’t provide a natural mechanism to cause this. It could have been the case that one party is much less radical than the other, so their median voter is much closer to the overall median voter, and they would win the general elections every time by a wide margin. Schematically, it would look like this.
It could be that the natural balance this causes is 60% of voters prefer the candidate of the more moderate party, and that party always wins by a similar very wide margin. But this is not what we see - general elections are in fact close, sometimes very close. What’s more, they are often closer in the metric that matters (in the US - electoral votes) than by metrics that don’t decide the winner (in the US - the popular vote). It could be pure coincidence - we don’t have that many elections with high polarization to make statistics, and electoral votes are more noisy than the popular vote. But it could also imply some version of the Median Voter Theorem effect going on. What form would it take to achieve this situation?
I mentioned before that we were making the assumption that voters in the primaries do not consider electability, but only their policy positions and those of the candidate. But that is a bit naive - we know voters also consider electability because it is openly discussed in the primaries. If voters in the primaries only decided according to electability, they would select candidates which are very close to the overall median voter (out of all voters in the general elections), and we would have the Median Voter Theorem applying again in the national elections, with both candidates having very moderate positions. If they only decided on the primary candidate closest to their preferred positions, we would not be able to explain the mystery of the general elections being close. That leaves us with a middle possibility - that voters in the primaries weight electability just enough so that they get a candidate with views close to theirs, but who has a chance to win with the general electorate. But they don’t make them too electable, otherwise the general elections would not be as close as they are. I still find it surprising that voters would be able to aim so precisely. And of course if one party’s voters in the primaries decided to weight electability a little higher, they could reach an equilibrium where they get 55% of the vote and win easily. The other party might respond by nominating a candidate which is also more electable, and we’d have the equilibrium of the Median Voter Theorem again, so it’s an unstable equilibrium and without resorting to some of the other explanations it’s hard to explain how it happens.
Hypothesis 5: the model is wrong
It could be that voters don’t base their votes on policy positions almost entirely. They are entrenched partisans, or have distorted views of the other party, vote to signal various things about themselves and so on. It could also be that politicians are polarized not in response to voters’ preferred positions, but due to their personal preferences instead of positioning themselves according to the optimal election strategy. I don’t want to go into all the ways this could go wrong, but I do think we have evidence that politicians react to the views of the electorate (they certainly change their views more often than personal preferences would imply), and this could also take the form not of a single politician changing their positions, but of other politicians with more favorable positions being elected.
Conclusion
I’m still a little confused by this. I don’t have a good model which explains both politicians’ polarization, and elections being very close. But I think the factors I pointed out play a role, and a combination of some of them could even be a full explanation. Or it could be something completely different. Maybe examples from other countries could shed light on this?
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[1] If we model voters on more than one dimension, the median is not defined. But it is still the case that if a candidate has positions closer to their opponent, they would get a larger share of the vote, so the same dynamic described here holds.
* Thanks to ZBH and ALB for reading an early draft of this post.