Judy Woodruff:

On this President's Day holiday, we're taking a look at presidential powers and how they have changed over time.

We're joined now by two presidential historians Douglas Brinkley, professor of history at Rice University and author of several books on the presidency. And Andrew Rudalevige, he's professor of government at Bowdoin College and the author of "The New Imperial Presidency: Renewing Presidential Power after Watergate."

And welcome to both of you.

Andrew Rudalevige, let me start with you.

How much more powerful is the American presidency today than it was either in the earliest days of this country or even 150 years ago?