Amity Shlaes has a tax column up at Bloomberg News:
In 1980, the top 1 percent of earners paid 19 percent of income taxes, and the bottom half of earners paid 7.1 percent. A decade later, with a lower maximum rate, the top 1 percent paid 25 percent of taxes, while the bottom earners paid just 5.8 percent. By 2008, top earners paid 38 percent of taxes, the bottom half 2.7 percent....
tax sanctimony gets in the way of tax reform. In a progressive rate structure, the rich almost always get bigger tax cuts, because their rates are higher to begin with. So their cuts sound unfair. The more progressive a tax structure, the more unfair its dismantlement appears.
The reality is that this year in tax terms, the U.S. isn't a sinner. The country is already clean. The very rich shoulder far more of the collective burden than their share in the population warrants.