We need to learn from history. These same leaders - [Barack] Obama, [Hillary] Clinton, and far too many Republicans - want to topple [Bashar] Assad. Assad is a bad man. Gadhafi was a bad man. Mubarak had a terrible human rights record. But they were assisting us - at least [Muammar] Gadhafi and [Hosni] Mubarak - in fighting radical Islamic terrorists.

The thing is, is that every terrorist attack we've had since 9/11 has been legal immigration.

Donald [Trump] is a charming person. He can be fun. He can make you laugh. But he can turn on you. And get nasty and personal and vicious.

A debate actually is a policy issue but I will say this - gosh, if you guys ask one more mean question, I may have to leave the stage.

About 65 percent of Republicans believe that Donald Trump is not the best candidate to go head to head with Hillary Clinton.

Any military force should be dictated by the vital national security interests of the United States. And if and when we use force, we should use overwhelming force for a clearly stated objective. And then when we're done, we should get the heck out.

Congress needs to send a strong signal that direct communication with the leader of the free world is a privilege, particularly for a regime that has been as hostile as Iran has been towards America for more than three decades. President Rouhani needs to take these two simple steps to demonstrate good faith before any further discussions.