Judy Woodruff:

And we take a deeper look now at the president's authority to declare a national emergency to fund that southern border wall with former Secretary of Defense Leon Panetta. He was the director of the Office of Management and Budget in the Clinton administration. He went on to serve as President Clinton's chief of staff.

He joins us now from Monterey, California.

Secretary Panetta, thank you for joining us again.

First of all, do you think the president has the constitutional authority to declare a national emergency over this issue that he's concerned about, the southern border?