Mitt Romney's taxes have been the subject of scrutiny lately, as his fellow GOP competitors—and allies—demand he release his tax returns. The frontrunner has said he will do so in April but, in the meantime, estimates he pays a tax rate of about 15 percent. In calculating his probable tax rate, Romney also revealed a key clue to just how wealthy he is. The former Massachusetts governor noted that he receives "speaker's fees from time to time, but not very much." However, USA Today reported back in August that Romney had earned more than $362,000 in speaking fees in one year, not exactly chump change. Unsurprisingly, at least one of Romney's opponents has latched onto this. Rick Santorum, who has refrained from joining his fellow Republican candidates in attacking Romney's record at Bain Capital, said, "To make a statement that I made a couple of extra bucks giving speeches when that couple of extra bucks was over $300,000—I mean, that to me says a little bit more about Governor Romney and his connection with the American people than his tax rate."