Republican presidential candidate Ron Paul became visibly irritated during a CNN interview on Tuesday after he was asked to explain 20-year-old racist newsletters that were written in his name, and have recently resurfaced.

"His newsletter, which he wrote and edited for years, was a constant organ of vile racism and homophobia," New York magazine's Jonathan Chait wrote last week. "This is not just picking out a phrase here and there. Fear and hatred of blacks and gays, along with a somewhat less pronounced paranoia about Jewish dual loyalty, are fundamental elements of his thinking."

Even conservative magazine The Weekly Standard has attacked Paul over the newsletters in their latest issue.

CNN host Ali Velshi gave Paul a chance to respond Tuesday.

"You refer to disturbances in Washington's Adams Morgan [neighborhood] as 'animals taking over the D.C. Zoo,' referring to African Americans," Velshi noted. "You said that Martin Luther King seduced underage girls and boys. You talked about Ronald Reagan proclaiming 'annual hate whitey day' with Martin Luther King Day. And you advocated prohibiting AIDS patients from eating in restaurants. These things were published under your name."

"Yeah, but I didn't write them and I disavow them," Paul insisted.

"But you're a presidential candidate. That's tough," Velshi observed. "It kind of comes back to bite you that you made money off of things that were published under your name that were hateful and racist."

"Yeah," Paul agreed. "But this has been addressed for 20 years and nobody accuses me of that type of belief or language. I'm a true civil libertarian, and I think people dig these up when people think that 'Oh, his economic policies are winning. His foreign policies are winning. His monetary policies are winning.' So, they have to dig these things up that they really can't pin on me."

"But I didn't write them and those aren't my beliefs. So, I sleep well," he added.

"Are you comfortable in telling us who did write them?" Velshi asked.

"I really don't know," Paul explained. "Twenty years ago, I had six or eight people helping me with the letter, and I was practicing medicine to tell you the truth. And so, I really do not know."

"Well, we could find out?" Velshi pressed. "Because you had six or eight people? Like, it was one of those six or eight people?"

"Well, possibly I could," Paul admitted. "These charges are a total contradiction of everything I've said and everything I believe."

As The New York Times pointed out Monday, the Texas Republican has been dealing with the fallout from his newsletters for years.

"They were never my words, but I had some moral responsibility for them," Paul told the Texas Monthly in 2001.

Watch this video from CNN's American Morning, broadcast Dec. 20, 2011.