Who doesn't pay federal income tax?

Seniors, students, active-duty military, the working poor...

There are a lot of people in the United States who pay taxes, but for one reason or another, don't pay federal income taxes. Mitt Romney says it's 47 percent (and they're all Obama voters...), but the number in 2011 was 46.4%, according to data from the Tax Policy Center.

But if you think these income earners pay no federal taxes at all, think again. Most (nearly two-thirds) of households that paid no federal income tax still paid payroll taxes (taxes that fund Social Security and Medicare).

The other third of households, those that pay no federal income tax or payroll taxes, most of them are senior citizens, and most of the rest are working households who earn less than $20,000 a year.

See for yourself (PDF):