Sometimes the political opinions can result in direct actions, but that is rather rare today. (I guess it is not like you and your friends are going to volunteer as soldiers for the opposite sides in Gaza.) The biggest "action" most people do is giving their vote. One vote of a few millions... perhaps our brains are not able to work with values like this, so we feel like our friends have at least 5% of the votes each.

But even when the "real" consequences of our opinions are close to zero, social consequences remain. As long as other people are polarized about some issue, you opinion about conflict in Gaza is essentialy a decision to join the "team Israel" or "team Palestine". This choice is absolutely unrelated to the actual people killing each other in the desert. This choice is about whether Joe will consider you an ally, and Jane an enemy, or the other way. With high probability, neither Joe nor Jane are personally related to people killing each other in the desert, and their choices were also based on their preference to be in the same team with some other people. But having made their choice and joined a team, their monkey brains were reprogrammed to feel very emotional about this topic. (Of course their answer would be that X are good people suffering from Y's evil actions -- and if sometime some X hurts some Y, that's just a self-defense or a deserved payback -- and if you don't see it the same way, well then there is something morally wrong about you.)

In some way, calculating the "mindkilling power" of a topic is like calculating a Page Rank of a web page. A web page has high Page Rank if many pages with high Page Rank link to it. And a topic is strongly mindkilling, if many people around you are strongly mindkilled about it. Somewhere it starts with someone having (or expecting to have) real consequences, but later it is mostly about the structure of social networks and relationships between the memes.