GEOFF BENNETT: Now, for a legal perspective on those new developments regarding President Trump's immigration agenda, we turn to William Banks, professor emeritus of law at Syracuse University.

Thank you for being with us.

And, as we have reported, the Supreme Court today lifted restrictions on immigration stops in the Los Angeles area, at least while this case plays out in the appeals court.

Lower court rulings found evidence that the raids swept up people simply for looking Latino or for speaking Spanish, raising Fourth Amendment concerns.

How should we understand the court's ruling in light of that?

WILLIAM BANKS, Professor Emeritus, Syracuse University College of Law: The most important thing to understand about what the Supreme Court has done today is that it's only temporary.

They paused the lower courts while a hearing on the merit can be held.

So whether the ICE immigration stops are based on a proven or unproven assertion of focusing on ethnicity or race has to be determined finally after there's been evidence submitted on a record.

So all the Supreme Court did today is that they're allowing the government to go forward with their immigration enforcement methods as they propose them at least while the litigation is pending.

This case is by far, far from any means over.

There'll be arguments on the merits about the Fourth Amendment, about the due process clause and perhaps even about the First Amendment.

GEOFF BENNETT: Well, on that point, how do immigration stops based on race, language or appearance square with the Fourth Amendment protection against unreasonable search and seizure?

WILLIAM BANKS: Justice Kavanaugh is the only justice to write a concurring opinion from among those in the majority today.

It was 6-3.

And Justice Kavanaugh said that his view was that the potential for ethnicity or race to be a factor in the immigration enforcement was one factor among many.

And if it's one factor among many that the government used to detain or stop or question an individual, that's not sufficient cause to enjoin or stop that aspect of the practice.

It's one among many.

So, often in policing, members of the law enforcement may utilize various individual characteristics like race or ethnicity or gender or anything, lifestyle, physical appearance, to question briefly someone on the street, so long as it doesn't effectuate an arrest, that person's liberty has not been taken, and the inconvenience of a temporary stop or a temporary detention, said Justice Kavanaugh anyway, should not stand in the way of the government going about its mission.

GEOFF BENNETT: Meantime, the Trump administration said today it started an immigration crackdown in Chicago.

The governor of Illinois, J.B. Pritzker, the mayor of Chicago, Brandon Johnson, are pushing back.

Does the president have the authority to send in federal agents over the objections of state and local leaders in this case?

WILLIAM BANKS: The president has the authority to send in civilians into the state of Illinois or city of Chicago, those that are working for ICE or some other civilian agency in the U.S. government, but he doesn't likely have the authority to deploy the National Guard there.

The reason for that is a fundamental one in our system, that National Guard forces are in their default posture subject to command of the state governor, not the president of the United States.

The president can only utilize the National Guard for a federal operation if the state governor agrees - - and, in this case, as you point out, he has not -- or if the president thinks that circumstances are truly extraordinary, he can invoke something called the Insurrection Act to federalize the incident altogether.

That would be a very extreme step, one that hasn't been taken in the United States since 1992 and that's been taken only a few times in our collective history.

GEOFF BENNETT: And Chicago, as you well know, has declared itself a sanctuary city.

How much power do local officials actually have to resist or limit federal law enforcement?

WILLIAM BANKS: Local officials, state officials have considerable leverage in this regard.

There's a concept that is taught in constitutional law in law schools everywhere that holds that the federal government may not commandeer state resources into service of a federal program.

In other words, President Trump or any president is free to send federal resources to do a federal job, to fulfill a federal mission inside a state, but they can't compel the state to provide assistance, to provide personnel, to provide whatever other resources the federal government might need.

GEOFF BENNETT: William Banks, professor emeritus of law at Syracuse University, thanks again for your time this evening, sir.

WILLIAM BANKS: Thank you.

It was good to be with you.