ERRR WRONG: http://www.usatoday.com/money/perfi/taxes/story/2011-09-20/buffett-tax-millionaires/50480226/1
The 10% of households with the highest incomes pay more than half of all federal taxes. They pay more than 70% of federal income taxes, according to the Congressional Budget Office.
You need the whole truth:
A number of studies by the US Department of Commerce, Congressional Budget Office (CBO), and Internal Revenue Service, have found that the distribution of income in the United States — most commonly measured by household or individual — has become increasingly unequal since the 1970s.
One of the most recent and comprehensive studies on the change in income inequality in America was a 2011 study by the Congressional Budget Office (CBO) -- "Trends in the Distribution of Household Income Between 1979 and 2007". (It chose those two years because they both preceded an economic recession and so both were periods of "similar overall economic activity"[43]). The report found that real household income after federal taxes and including government transfers (payments from Social Security, unemployment insurance, etc.[44][45]) grew by 62%.
However, income of households in the top 1 percent of earners grew by 275%, compared to 65% for the next 19 percent, just under 40% for the next 60 percent, 18% for the bottom fifth of households. "As a result of that uneven income growth," the report noted, "the share of total after-tax income received by the 1 percent of the population in households with the highest income more than doubled between 1979 and 2007, whereas the share received by low- and middle-income households declined … The share of income received by the top 1 percent grew from about 8% in 1979 to over 17% in 2007. The share received by the other 19 percent of households in the highest income quintile (one-fifth of the population as divided by income) was fairly flat over the same period, edging up from 35% to 36%." [46]
http://en.wikipedia.org/wiki/Income_inequality_in_the_United_States