"Fox News Sunday" host Chris Wallace on Sunday challenged Sen. Marco Rubio (R-FL) to explain why he pulled his support for the Senate bipartisan immigration reform bill.

Wallace displayed polls showing Rubio's favorability taking a hit since supporting the bill.

"Is that why you have now switched and said we have to do this in stages with enforcement first and any dealing with legality or citizenship for the immigrants way down the line and afterward?" Wallace asked.

Rubio said his stance on immigration reform has nothing to do with politics.

"When I got involved in the issue, I knew how difficult it was politically, but I ran for office to make a difference," he responded. "I didn’t get elected to maintain good poll numbers nationally."

Wallace then cut in to ask, "If it’s not political, why have you flipped?"

"That’s not accurate, Chris," Rubio insisted.

The senator said he and Wallace were "talking about two separate things."

"We're not debating what to do. We're debating how to do it. And I’m just telling you we will never have the votes necessary to pass in one bill all of those things. It just won't happen," Rubio said. "So, our choices are: We can either continue to beat our heads against the wall and try a process for which we will never have the support, or we can try another way that we could perhaps make progress on."