Senate Majority Leader Harry Reid reportedly is not backing down from his assertion that Mitt Romney hasn't paid taxes in 10 years.

The Las Vegas Review-Journal reports Reid said the controversy could end if Romney revealed more of his tax information.

Asked again whether he'd reveal the source of his information, the Nevada Democrat said "I've answered your question," according to the Las Vegas newspaper.

Romney has repeatedly said Reid's claim, based on a "credible source" who is an investor in Bain Capital, is untrue and that he has paid his taxes. The flap escalated this weekend with a round of name calling on the Sunday morning talk shows.

Republican National Committee Chairman Reince Priebus called Reid a "dirty liar" on Sunday, and Reid aide David Krone told Politico that such Romney supporters are "henchmen" and "cowards" for their attacks on the Senate majority leader.

The Wall Street Journal's editorial page, which sometimes has been critical of Romney, slams Reid in a column today urging the majority leader to "stay classy." Although the editorial says Romney could resolve the issue by releasing more tax documents, it chastises Reid's tactics.

"But without any proof, Mr. Reid's accusations are a smear from the fever swamps that say more about Mr. Reid's ethics than they do about Mr. Romney's taxes," the WSJ editorial says.

President Obama and his Democratic allies have frequently criticized Romney's wealth and his refusal to release more tax information. Romney has posted on his website his 2010 tax return and an estimate of what he paid in 2011, and says he'll release the return for the last tax year when it is ready.

With a net worth of $190 million to $250 million, Romney is one of the wealthiest men running for president in a couple of decades. Sometimes, his own comments -- such as those about his wife owning two Cadillacs or his friendship with NFL and NASCAR team owners -- have left Romney open to criticism that he's out of touch with the average American.

Still, it's unclear whether Reid's charges will hurt the Democrat back home. He survived a stiff re-election challenge and defeated Republican Sharron Angle, a Tea Party favorite, by 6 percentage points in 2010. Reid, an amateur boxer in his youth, isn't up for re-election again until 2016.