TAMPA, Fla. (AP) — Republican presidential candidate Mitt Romney says his tax returns will show he pays all taxes that are legally required and, in his words, "not a dollar more."Romney is set to release his tax returns Tuesday morning. Asked during Monday night's debate what the returns will show, Romney says they will outline his total income, total taxes and significant charitable contributions.Romney won't say what he thinks will be the most politically problematic part of the returns. He says the returns will show the returns are "entirely legal and fair."Gingrich says he wants to allow Americans to be able to choose a flat tax of 15 percent. That's the tax rate Romney says he pays.