US Supreme Court hears challenge to Trump travel ban

The travel ban applies to mostly Muslim-majority countries.

Solicitor General Noel Francisco argued for the administration that the latest ban was the result of a "worldwide multi-agency review," was based on "foreign policy judgment" rather than religious animus, and excludes "almost all the world - including almost all the majority-Muslim world."

Francisco urged the court not to focus on the words of candidate Donald Trump, saying that a president-elect taking the oath of office "marks a fundamental transformation."

"This is not a Muslim ban. If it was it would be the worst Muslim ban in the world," Francisco said, because it excludes the vast majority of the Muslim world.

Neal Katyal, acting Obama solicitor general, argued for the challengers, saying "the president can't take a wrecking ball" to the congressional immigration law they say he violated in trying to impose the ban, adding that if the justices voted to uphold his action "you'd be giving the president a power that hasn't been given in 100 years."

Kate Shaw, ABC News Supreme Court contributor and a professor at Cardozo Law School, breaks down the case.

What’s at issue in this case?

This case involves a challenge to the Trump administration’s most recent attempt to restrict entry into the U.S. by individuals from particular countries, most of which are Muslim-majority.

Chaos in the country's airports immediately ensued, and a number of federal courts swiftly enjoined the order nationwide. After losing in the Ninth Circuit, the administration decided to abandon further efforts to defend the order, and instead withdrew and replaced it with an order that differed slightly from the first, but whose reach and effects were similar. The second order also faced successful challenges in a number of lower courts, but in June 2017 the Supreme Court allowed it to go partially into effect. After the order expired by its own terms, the Trump administration replaced it with the Proclamation under review in this case.

Who are the plaintiffs and what are, in this case,?

The plaintiffs in this case are the state of Hawaii and several private individuals. Hawaii bases its claims of injury on its state university system, arguing that the Proclamation has an adverse impact on both current and prospective scholars who might wish to affiliate with the university system. The individual plaintiffs argue that they have been prevented from reuniting with close relatives who have applied for visas from one of the covered countries.

What about the Trump administration’s arguments?

Anything in particular to watch for during oral arguments?

The case will be argued by two excellent lawyers: Neal Katyal, who was acting solicitor general under President Barack Obama, will argue for Hawaii, while current Trump Solicitor General Noel Francisco will represent the administration.

Another important justice to watch here is Justice Neil Gorsuch, whose views on presidential power we don't really know yet. Gorsuch joined the liberals to rule against the Trump administration in an immigration case last week, evidently to the deep displeasure of the president, so I'm sure the Trump White House will be keenly interested in Gorsuch's questions and tone during the arguments.

Listen to the case: