Mitt Romney and Paul Ryan are understandably reluctant to explain the specifics their tax plan, because then they'd have to admit that it is mathematically impossible for them to institute their proposed cuts for the rich without raising the middle-class's tax burden. Unfortunately for the Republican candidates, people (especially those employed by the Obama campaign) continue to press for details, forcing them offer up increasingly unsatisfying evasions. Today's non-explanation — which took place during Ryan's appearance on Fox News Sunday — was particularly silly-sounding.

Ryan reiterated...that the plan would drop taxpayers' bills by 20 percent without costing a dime, due to closed tax loopholes, but he was short on specifics when pressed by host Chris Wallace.

“You haven’t given me the math,” Wallace said in one exchange.

“I don’t have the ... It would take me too long to go through all of the math,” Ryan responded.