Most Americans vote against their self-interest

I found this graph, by Andrew Gellman, quite interesting:

No, not the obvious thing -- that rich people vote republican and poor people vote for Democrats (he considers only whites, so it's not about race).

No, the thing I am surprised by is how pervasively Americans vote against their self-interest.

Only the undereducated show no impact of the news that they read and the circles they run around in.  If they are poor, they vote for democrats but if they are rich, they vote for Republicans.  In other words, they vote their self-interest quite logically.

People with some education (high school graduates and BS degree holders) start off with much higher levels of voting for Republicans.  Even when poor, they vote for Republicans (against their self-interest: this is the thesis of the famous book "What's wrong with Kansas?"). This must be an impact of the cultural war.  Simply put, these people believe Democrats look down upon them and so they feel more comfortable with the simple truths told by the right-wing echo chamber.

Meanwhile, people with graduate degrees, even if they are rich, vote against their self-interest, voting for higher taxes and voting for the government to give their money away to the poor (surely, they could that themselves?). Again, the reason is not hard to see.  An anti-science party that disparages education at every turn is hard to side with even if it would be better for your wallet.