Harry Reid, D-Nev. has no regrets about his 2012 claims that then presidential candidate Mitt Romney paid no taxes for 10 years.

The outgoing Senate Minority Leader even bragged to CNN that the comments, which had been described as McCarthyism, helped keep Romney from winning the election.

"They can call it whatever they want. Romney didn't win did he?" Reid said during a wide-ranging interview.

So, in Reid's world, it is perfectly acceptable to make a defamatory charge against an opponent to damage his campaign.

Reid first made the accusation against the former Massachusetts governor in a 2012 interview with the Huffington Post. At the time, Reid claimed that a Bain Capital investor told him Romney didn't pay taxes for the previous 10 years. This, Reid claimed, was why Romney hadn't released his tax returns.

"He didn't pay taxes for 10 years!" Reid said. "Now, do I know that that's true? Well, I'm not certain, but obviously he can't release those tax returns. How would it look?"

A few days after the HuffPo interview, Reid made the same charge on the Senate floor, this time claiming as fact that Romney paid no taxes.

"As we know, he has refused to release his tax returns. If a person coming before this body wanted to be a Cabinet officer, he couldn't be if he had the same refusal Mitt Romney does about tax returns," Reid said. "So the word is out that he has not paid any taxes for 10 years. Let him prove he has paid taxes, because he has not."

Even though Reid made a slanderous statement that Romney had in fact paid not taxes, without mentioning anything about his Bain source or skepticism, he cannot be sued for that particular statement. Article I, Section 6 of the Constitution states that members of Congress shall "be privileged from arrest during their attendance at the session of their respective Houses, and in going to and returning from the same; and for any speech or debate in either House, they shall not be questioned in any other place." The only exceptions to this rule are for treason, felonies and "breach of the peace."

After his floor speech, Reid made the claim again, except this time he again cited his "extremely credible source" for the accusation.

So when Reid directly accused Romney of being a tax dodge, he did so from the safety of the Senate floor. Outside the protection of legislative immunity, Romney was only possibly a tax dodge.

Not only does Reid not think he did anything wrong, he's actually proud that his lies might have helped cost Romney the election.

Note: The Washington Post's fact checker gave Reid "4 Pinocchios" for his claims. PolitiFact gave the claim a "pants on fire" rating.