What were the labels in the 2009 surveys, exactly? I am a libertarian socialist, and in the 2011 survey I voted “socialism” because the examples made clear that the American (capitalist) meaning of libertarianism was intended, but if the options had been simply labelled “socialism”, “libertarianism” etc. with no example I would have voted the latter. If there are many other libertarian socialists around, this might explain much of the difference between the 2009 and 2011 results.

The relative proportions of liberalism, libertarianism, and conservatism haven't changed much, and I don't think we can say much about five new communists; by far the most significant change appears to be the doubled proportion of socialists. So this doesn't look like a general loss of metacontrarianism to me.

I'm not sure how to account for that change, though. The simplest explanation seems to be that LW's natural demographic turns out to include a bunch of left-contrarian groups once it's spread out sufficiently from OB's relatively libertarian cluster, but I'd also say that socialism's gotten significantly more mainstream-respectable in the last couple of years; I don't think that could fully account for the doubling, but it might play a role.

And the large increase in population seems to include a large portion of students... which my experience tells me often has a higher-than-average portion of socialist leanings.