This is the Cato Daily Podcast for Friday, February 24th, 2017. I'm Caleb Brown.

President Trump's plans to get local law enforcement more involved in enforcing federal law will be done with the carrot and stick of federal funding.

But the Supreme Court has already ruled that denying states big piles of federal funds if they

don't behave in certain ways is unconstitutional.

So how much is too much?

Cato adjunct scholar Josh Blackman comments.

President Trump on the campaign trail and in, since he has taken office has said,

we got to get rid of these sanctuary cities.

You know, speaking to his crowd,

how many of you want to get rid of these sanctuary cities, which of course is something the feds cannot do unilaterally,

but they can tie federal funding to certain behaviors that they want state and local governments to adopt.

So the question is, how much funding can they take away that courts have clearly adjudicated well this is too much or this is too little?

So your question is exactly on the right path.

There are two doctrines here. First is what's known as the

commandeering doctrine. Congress can't force a state or state officials to fulfill a federal

program. They can't say to a local police officer, you are required to remove aliens who are not here lawfully.

That's illegal. But what the feds can do is condition money saying,

hey, you want this grant?

Wonderful.

You have to do X, Y, and Z.

So the argument becomes, can the Trump administration

hold back money from sanctuary cities that refuse to share

...