Out of regime change you get chaos. From the chaos you have seen repeatedly the rise of radical Islam. So we get this profession of, oh, my goodness, they want to do something about terrorism and yet they're the problem because they allow terrorism to arise out of that chaos.

40 percent of people who come to visit America on a visa overstay their visa and we have no idea where they are. On 9/11, at least 2 of the hijackers were here on visa. They were traveling back and forth to the Middle East. And we really had no idea where they were or what they were doing. And they were overstaying their visa. So there are problems I think in the immigration system that need to be fixed for our safety.

The main thing I say on war is that we need to obey the law and formally declare war.

I think that if you believe in regime change, you're mistaken. In 2013, we put 600 tons of weapons - us, Saudi Arabia, and Qatar - into the war against [Bashar] Assad. By pushing Assad back, we did create a safe space.

For most of our history, no one dared to tell Americans, you don't build that.

I have allowed the president to pick his political appointees…But I will not sit quietly and let him shred the Constitution.

On the Gang of Eight bill, there was no provisions really for extra scrutiny or safety for refugees. At the time the bill came up, two Iraqi refugees came to my home town, Bowling Green, Kentucky. Their fingerprints were on a bomb from Iraq. They were in the database, but we didn't pick them up.