One week after Senate Majority Leader Harry Reid charged that Mitt Romney did not pay taxes for 10 years, the flap over the remark doesn't appear to be dying down at all.

The charge popped up as a major point of conversation on the Sunday show circuit, with high-ranking Republicans like RNC Chair Reince Priebus firing back at Reid and calling him a "dirty liar."

Reid's charade doesn't look like it's going to fizzle out any time soon. He's going to keep insisting that the "Bain Capital investor" who told him about Romney's tax returns is legitimate. Why? Because he's playing a game with virtually no chance of losing.

Let's break it down:

Romney has backed himself into a corner that will be tough to get out of. If he relents to Reid's demands, then Reid wins. If he doesn't, then Reid and other Democrats will keep making it an issue.

Reid has pretty successfully made this issue a loaded question. The only way to completely disprove Reid is to release the tax returns. And if he doesn't, it will add to the perception that there's something veiled behind his "put up or shut up" words. Because...

Keep in mind that a majority of voters — and, crucially, Independent voters — want Romney to release his tax returns, according to Gallup. In the clearest sign that Romney has bungled this issue, most people think that a presidential candidate's tax returns are irrelevant , except in Romney's case.

Reid doesn't have to worry about re-election — if, at 76 years of age, he will seek re-election — until 2016.

Several Republicans and the Romney campaign have accused Reid of Joseph McCarthy-style witch hunt or compared Reid's charges to the "birtherism" movement from conservatives that still has some legs. It's not. Accusing Romney of not paying taxes is a far less serious charge than accusing the President of treason. And it's not really a "witch hunt," either. It's just a more serious — albeit baseless — charge than any Democrat has been willing to throw out on the record.

As long as Romney continues to be rattled by this, this is an issue that will continue to knock Romney off message.

Further evidence that this story has legs came Monday, when House Minority Leader Nancy Pelosi backed up Reid today in an interview with The Huffington Post.

"Harry Reid is a person who is, as we know, A, is a fighter, B, he wouldn't say this unless it was true that somebody told him that," Pelosi said.