Socioeconomic status, ideology & party

Andrew Gelman has a post up, Who are the liberal Democrats and the conservative Republicans?, which shows that conservative Republicans tend toward higher incomes, while conservative Democrats tend toward lower incomes. I decided to see if something similar was discernible in the General Social Survey. I used the PARTYID, POLVIEWS and SEI variables to explore the question, and limited the sample to whites and the years 1998-2008 (so as to have contemporary relevance and control for ethnic confounds). I clustered all Republicans & lean Republicans into one category, and did the same for Democrats. I also clustered all who were liberal and conservative into one category (extremely to slightly). Finally, socioeconomic status ranges from 17 to 98, and I broke it into three categories of "low," "middle" and "high," 17-47, 48-77 and 78-98. The percentages in the population for these three categories were 54%, 36% and 11%, so "low" is really lower to lower middle class. In any case, the charts below....

The same general trend as in the data Gelman reports; conservative Democrats tend to be lower socioeconomic status, while conservative Republicans are higher status. Since the intelligent and educated are more ideological this makes sense. Over the past generation more Americans routinely have labelled themselves Democrats than Republicans and conservatives than liberal, but both Democrats and conservatives have been confused as to why they can't always translate their numbers in polls into permanent dominance in politics. I suspect there's some sort sentimental preference in people labeling themselves Democrats and conservatives which doesn't really reflect much in terms of their voting or the realized preferences contingent upon their voting.