07/17/2012 05:44 pm ET

Why Romney's Tax Returns Remain Hidden: Our Theories (CHART)

Of all the problems Mitt Romney's presidential campaign is facing, perhaps the most conspicuous is his reluctance to release his tax returns, a tradition of presidential candidates started by Romney's own father George when he ran for president in the '60s.

Both the right and left have become increasingly vocal in asking Romney to release his records, and his excuses -- lately, that he's "simply not enthusiastic" about releasing them -- only add to the suspicion that he may be hiding something.

When your biggest defender on this matter is Donald Trump, you don't exactly have credibility in this area, Mitt. Why you refuse to release them, we don't know, but we have a few ideas of our own.