Inequality Unequaled, or, Reasons to Vote Obama
The Census Bureau has tracked the economic fortunes of affluent, middle-class and poor American families for six decades. According to my analysis, these tabulations reveal a wide partisan disparity in income growth. The real incomes of middle-class families grew more than twice as fast under Democratic presidents as they did under Republican presidents. Even more remarkable, the real incomes of working-poor families (at the 20th percentile of the income distribution) grew six times as fast when Democrats held the White House. Only the incomes of affluent families were relatively impervious to partisan politics, growing robustly under Democrats and Republicans alike.
From the New York Times article. Go read it.