This is the Cato Daily Podcast for Thursday, January 20th, 2010.

I'm Caleb Brown.

The Constitution is popular these days, but precisely how does it constrain federal power, particularly the powers of

the President and Congress.

Bob Levy is chairman of the Cato Institute.

We sat down in November and talked for more than 30 minutes on several subjects relating to how libertarians think about the Constitution and where libertarians differ from modern conservatives and liberals.

This is the first of a two-part discussion. We have a new Congress

led by an energy from a group that claims fealty to the Constitution. They're

worried about adherence to the Constitution by the federal government.

What are the three or four big principles that these people and the voters who put them in

office need to consider.

I think the three key principles underlying the US Constitution

are enumerated powers, federalism,

and separation of powers.

And taking those one at a time,

the principle of enumerated powers is fairly straightforward.

It starts with the very first sentence to the Constitution, which says all legislative powers here and granted are vested in Congress.

Now those two terms, two words here and granted, are critically important.

And what it suggests is that there are no powers

other than the ones that are here and granted.

And then later in the Constitution,

they're laid out just in case anybody

...