You would expect Republican politicians to struggle with answering questions about Mitt Romney's "47 percent," conflicted between party loyalty and their own electoral welfare. But for Democrats, the answer should be easy. Not so for Tim Kaine, the former governor of Virginia who's running for Senate against George Allen. In a debate between Kaine and Allen Thursday, NBC News’ David Gregory asked Kaine, "Do you believe that everyone in Virginia should pay something in federal income tax?" As Slate's Dave Weigel explains, Kaine struggled to answer.

Kaine: Well, everyone pays taxes! I mean, the statistics that have come out..

Gregory: I'm asking about federal income taxes.

Kaine: I would be open to a proposal that would have some minimum tax level for everyone. But I do insist, many of the 47 percent that Gov. Romney was going after pay a higher percentage of their income in taxes than he does.

Oops. Now Kaine's in favor of raising taxes on poor people. It's a fairly lonely position too -- as Weigel explains, only Michele Bachmann would occasionally float the idea of poor people paying a few symbolic bucks to keep some skin in the game.