CHART: As Income For The Top 1 Percent Grew, Republicans Became More ‘Polarized’

Last week, ThinkProgress reported studies by political science professors Keith Poole and Howard Rosenthal that show House Republicans are largely responsible for the ideological extremism that has occurred over the last 30 years in Congress. Another study by Poole, Rosenthal, and others finds that as the proportion of income made by the top 1 percent has increased, members in the House have become more “polarized.”

Combining the two studies, meanwhile, shows that as the income of the 1 percent rises, Republicans become more polarized by moving further to the extreme right. The data sets affirm what we already know: the GOP is beholden to the interests of the 1 percent.

Poole and his colleagues explain this phenomenon by proposing that the top 1 percent tend to be highly partisan. As the income for the 1 percent rises, their campaign contributions become more partisan as well. This polarized campaign-giving has clearly contributed to the ideological extremism of the GOP, while the same type of donations have made only a negligible difference in the Democratic Party’s ideology.

Yet Republicans continue to ignore that America is now more unequal than Iran, Uganda, the Ivory Coast, and even Ancient Rome. And more to the point, as the income of the top 1 percent has seen a 275 percent increase from 1978 to 2007 (compared to a mere 18 percent increase for the bottom 20 percent), Rick Santorum says he is “for income inequality” and Mitt Romney attacks people who raise these facts as engaging in the “bitter politics of envy.”