Democrats counter that the rich pay more in taxes only because they've been getting richer. Yes, but no one knows how to stop them from getting richer as long as the economy is growing, and it wouldn't help anyone to try anyway. By any standard, they pay their fair share. As they pony up almost 40 percent of federal income taxes, the top 1 percent earn a little more than 20 percent of the nation's income.
Federal income taxes aren't the whole picture. People lower down on the income scale still have to pay the payroll tax to fund programs like Social Security. Even here, though, the rich bear the heaviest burden. The top 20 percent paid more than 44 percent of payroll taxes in 2004, according to the CBO.
As for the debate over the rebate, if the (dubious) premise is to kick-start the economy by scattering money around, lower-income people paying no income taxes might as well be included, as they are in the White House-congressional deal. But the moment shouldn't pass without noting what it tells us about the tax system supposedly being skewed toward the rich. It is not, except in the sense that it exacts more taxes from them.