Mitt Romney pulled out the dry erase board Thursday, for an impromptu lesson on the differences between his Medicare plan and the President's.
"Which of these two do you think is better? Going bankrupt or being solvent? Well obviously, being solvent," Romney said.
But while he wanted to talk Medicare, he couldn't get away from the question that's been dogging him for months: Why won't he release more of his income tax returns?
"I just have to say, given the challenges that America faces - 23 million people out of work, Iran about to become nuclear, one out of six Americans in poverty - the fascination with the taxes I paid I find to be very small minded compared to the problems that we face."
Romney was asked during his trip to Israel to tell the lowest rate he's ever paid in taxes. He said then he could go back and look. This time, he had an answer.
"I did go back and look at my taxes and over the past 10 years I never paid less than 13 percent."
Democrats have hinted that Romney's refusal to release more than two years of tax returns must mean he's hiding something. On Thursday, Romney again disputed harry reid's charge that according to a source, Romney paid no taxes some years.
"I've paid taxes every single year. Harry Reid's charge is totally false. I'm sure waiting for Harry to put up who it was that told him what he says they told him."
The Obama campaign issued a statement saying..."since there is substantial reason to doubt his claims, we have a simple message for him: Prove it."
In an interview Thursday night, Ann Romney said the couple will not release more than two years of tax returns because it would just give Democrats more ammunition to use against them.
(Susan McGinnis, CBS News)