Marco Rubio: Ted Cruz is not such a "purist" on immigration

Florida Sen. Marco Rubio believes his opponent for the Republican presidential nomination, Texas Sen. Ted Cruz, is not being completely straight with voters when he pitches himself as the only purely conservative candidate in the field on the issue of immigration.

"I think when you spend your whole time telling people that you're a clear talker, and you say what you mean, and everyone else is a sellout, but you're the only purist, I think it's fair to say, 'Well, hold on a second. I mean, here's where you've been in the past on some issues. And here's where you are now,'" Rubio told "Face the Nation" during a sit-down interview in Iowa that will air on this Sunday's broadcast.

During this week's GOP primary debate, Cruz came at Rubio hard over the issue of immigration.

"I led the fight against his legalization and amnesty," the Texas senator said at one point. "He was fighting to grant amnesty and not to secure the border, I was fighting to secure the border."

Rubio took issue with Cruz's attacks in our interview. "The truth is everyone running on the Republican side supports strong, conservative positions," he explained. "We have some differences on some issues. And we should discuss those, like national security, for example. But when you run by telling everybody you're the only purist in the field, you're the only one that's always consistent conservative, well, I think then your record is going to have a light shown on it."

Rubio suggested Cruz has previously embraced a path to legalization - but not citizenship - for undocumented immigrants living in the U.S., implying the differences between them on the issue are not as deep as Cruz has claimed.

"In fact, well after the immigration debate had ended, he was still talking about how he was open to legalizing people and how important it was to bring people out of the shadows and so forth," Rubio explained.

Tune into "Face the Nation" this Sunday to see more of our interview with Rubio. Check your local listings for airtimes.