Mitt Romney was almost correct that 47% of Americans don't pay federal income taxes — the exact figure for 2011 is 46.4% of American households.
But the vast majority of those households do pay a federal tax based on wages: the payroll tax, which funds Social Security and Medicare.
That means 18.1% of households pay neither the federal income tax nor the federal payroll tax. Of those, over half consist of retired, elderly Americans. And most of the rest are the working poor who qualify for the Earned Income Tax Credit, which is a Republican policy that gives tax breaks to low-income workers in lieu of a higher minimum wage.
And don't forget that federal taxes aren't the only kind of taxes. There are various state and local taxes, like property tax and sales tax. The notion that large swaths of Americans are unfairly mooching off government is just not true.