Andrew Gelman has some interesting graphs:
Some cool graphs of rich states and poor states, by Andrew Gelman: I'll take advantage of Paul Krugman's recent link to our paper on income and voting by putting up some cool scatterplots that we made recently. It started with our maps of which states Bush and Kerry would've won if only the votes of the poor, middle-income, and rich were counted:
We noticed that the familiar red-blue pattern (rich northeast and west coast supporting the Democrats, rest of the country supporting the Republicans) showed up clearly among rich voters, but not among the poor or middle class.
There are also some interesting scatterplots in Andrew's post. Summarizing the plots:
[F]or each income category, we show Bush's vote share for each state, plotted along with the state's income. For poor voters, there is no systematic difference between rich and poor states. But for middle-income and especially for rich voters, there is a very strong pattern of rich states supporting the Democrats and poor states supporting the Republicans.