Ira Stoll on Paul Ryan and Mitt Romney's Conflicting Tax Visions

"My plan is not like anything that's been tried before," Mitt Romney said at the first presidential debate. "It is mathematically possible. It's been done before," said Paul Ryan at the first vice presidential debate. 

Maybe, writes Ira Stoll, the next debate should be between Mitt Romney and his running mate, Paul Ryan, about what exactly is in their tax plan.