Rubio was grilled by nationally syndicated radio talk show host Mike Siegel, who said he's against the bill "because it violates the law that presently exists on the books."
Rubio responded: "It's a pretty tough road. It's not perfect but I think it's better than leaving them here the way they are right now," and added it's time to "clean up this mess and make sure it never happens again."
But Siegel thinks Rubio's push on immigration could hurt him if he decides to run for the 2016 GOP presidential nomination.
"He's disappointing his base and I think it's going to hurt him politically."