Texas Gov. Rick Perry was booed by the audience after he discussed his rationale for giving in-state tuition to the children of undocumented immigrants in his state, an Achilles' heel for the border-state governor when it comes to hard-line conservatives.

"There is nobody on this stage who has spent more time working on border security than I have. For a decade I’ve been the governor of a state with a 1,200-mile border with Mexico," he said, adding that he supported Arizona's immigration law and heavier patrols on the border.

"But if you say that we should not educate children who have come into our state for no other reason that they have been brought there by no fault of their own, I don’t think you have a heart," Perry continued. "We need to be educating these children because they will become a drag on our society ... I still support it greatly."

In response, the Republican crowd in Orlando, Fla., booed heartily.