DANA PERINO (CO-HOST): John Yoo is a former deputy assistant attorney general, one of our best legal minds that we have on the show, and I'm curious how you see this national emergency. Do you think the president has the legal authority to do it for this issue?

JOHN YOO (FORMER DEPUTY ASSISTANT ATTORNEY GENERAL): Dana, I think the question that many people are fighting about is the policy. But, I think, on legality, President Trump is on solid ground. If you think about it, as we've talked about on the show before, the whole purpose of having a president, the reason the founders created it, was that some branch of government could respond quickly, decisively, swiftly to emergencies and crises.

Previously:

On Fox, John Yoo says Trump could fire Sessions and Rosenstein for not investigating things he orders them to

These conservative media figures are pushing Trump to declare a national emergency over a border wall

Torture memo author John Yoo has the audacity to criticize Obama over the Ghailani trial