Rubio: Gingrich made 'right decision' in pulling ad

"I think Speaker Gingrich made the right decision," Rubio, who had decried the ad earlier this week, said during an interview Thursday morning on CBS. "I've known Speaker Gingrich for a long time; I'm an admirer of him; I think he made the right choice."

Rubio said he wanted the ad pulled because he felt it was inaccurate — and might come back to haunt the eventual Republican nominee.

"I didn't think the ad was accurate, I didn't think it had a place in this campaign," Rubio said. "I want to make sure we don't have candidates out there saying things that we're going to have to defend or clean up in the fall when we have to campaign in Florida."

But Rubio insisted he had not chosen a favorite in the hotly contested GOP primary.

"Nice try," he laughed in response to a question on the subject, going on to say that he believed all the candidates had shown growth and that he believed "they all are offering good plans."

He also continued to downplay vice presidential speculation.

"It's very flattering. I'm focused on two things — my job in the U.S. Senate … and I want to help the nominee, I don't think it will be as the vice presidential nominee, though," Rubio said.

Rubio also defended his criticism of President Obama as "divisive," saying his State of the Union promoted class warfare.

"The only way for some people to be better off is that other people will be worse off," Rubio said.