Of the people who don't pay income taxes in a given year, a growing number of them are fairly well-off, according to the Wall Street Journal:
We have heard, of course, about the low-income nonpayers. Opponents of taxes and government, in describing the excessive tax burdens of the wealthy, often cite IRS figures showing that the top 1% earn 22% of the nation’s income and pay 38% of the nation’s federal income taxes, while 47% of Americans pay no federal income taxes.
Yet there are plenty of high earners who also pay no taxes. They are called “HINTs” — High-earners, no taxes. They are the personal-income versions of General Electric, and their numbers are rising rapidly.
According to an article by Tom Herman in The Fiscal Times, more than 10,000 Americans who earned more than $200,000 in 2007 paid no income taxes to the U.S. government.
Granted, 10,000 is a small fraction of the people who escape income taxes. But it is a useful rejoinder to the usual right-wing attacks on people (mostly poor) who don't make enough to pay federal taxes (but who, it's worth noting, still face regressive state and local taxes).