Of the last four presidential elections won by the Republican candidate, the two closest ones (in 1980 and 2000) would have gone to the Democrat had lower-income people voted in the same percentages as higher-income groups. So suggests an analysis of data from the General Social Survey, a personal interview survey of a representative sample of U.S. households conducted regularly by the National Opinion Research Center at the University of Chicago.

So says Esther Cervantes and Amy Gluckman in the January/February issue of Dollars and Sense. What is more, the differences in voting preference between the rich and the poor seems to have increased, even as voter turnout amongst the poor remains low:

In 2000, a majority of voters in the lowest four out of five income quintiles reported choosing the Democratic candidate. In 1980, a majority of voters in three out of five income quintiles reported choosing the Democratic candidate, and the fourth quintile was nearly tied. Low- and middle-income people are far less likely to vote, however. As the table shows, the GSS data suggest that there is typically a 25 to 30 percentage-point gap in participation between the lowest and highest income quintiles. The data for every election show a clear pattern: turnout and the portion of the vote going to the Republican candidate both rise as income increases.