Mitt Romney's campaign attacked Senate Majority Leader Harry Reid, D-Nev., as a modern-day Joe McCarthy in response to Reid's repeated claims that Romney has committed tax fraud.

Reid has made the accusation over a period of days, most recently when he claimed this morning that Romney must "prove that he has paid taxes, because he has not." He told reporters yesterday that the burden is on Romney to prove that he is innocent, not on himself to prove that his accusation is true.

Romney's team said that "Harry Reid's charges are baseless and they're untrue" on Fox News.  "I would ask him one simple question," Romney top aide Eric Fehrnstrom said on Fox. "Have you no sense of decency, sir? Is there nothing that you won't do to debase yourself and your office in the name of dirty politics?" Fehrnstrom was quoting Joe Welch's question to Sen. Joe McCarthy during a hearing by the House Committee on Un-American Activities.

Asked if there was any truth behind Romney's claim, Fehrnstrom said,  "I'm telling you -- authoritatively, speaking on behalf of the governor -- that those charges are untrue; they're baseless, and there is nothing to back them up."

Fehrnstrom reiterated that "this reminds me of the McCarthy hearings back in the 1950s,"  before saying that Welch's question should be posed to Reid.

Reid refused to provide evidence for the charge. “I don’t think the burden should be on me,” Reid told reporters on a conference call yesterday. “The burden should be on him. He’s the one I’ve alleged has not paid any taxes."