The Texas congressman said that the articles - which did not carry a byline - were written by his publishing staff and that he did not know about them at the time.
"I didn't write them, I didn't read them at the time, and I disavow them. That is the answer," Paul said.
When CNN chief political analyst Gloria Borger defended her questioning as legitimate - noting that some of the articles were "pretty incendiary" - Paul began to remove his microphone.
The newsletters, mainly a forum for essay's on Paul's brand of libertarianism, once referred to Martin Luther King Jr. as "the world-class philanderer who beat up his paramours" and who "seduced underage girls and boys."
In another article, the author writes that "given the inefficiencies of what DC laughingly calls the criminal justice system, I think we can safely assume that 95 percent of the black males in that city are semi-criminal or entirely criminal."
The newsletters have long been an issue for Paul. In 2008, the congressman explained that he did not know who had written the offending essays and that they did not represent his views.
Before leaving the CNN interview, Paul admitted to having made money off the publication of the materials, but disputed a report in the New Republic that he had earned more than $1 million from the newsletter.
"I'd like to see that money," Paul said.
But the congressman - who some polls had leading in Iowa earlier this week - insisted that the newsletters were not an issue.
"I didn't write 'em, I disavow them, that's it," Paul said.