The lawsuit, brought by attorneys general of Washington and Minnesota, has captivated the nation since last Friday when a federal district court judge put a stop to Trump's executive order restricting travel for foreign nationals, and as a result, temporarily opened US borders to immigrants once again.
US District Court Judge James Robart upended Trump's executive order nationwide Friday by temporarily halting the key provisions restricting travel for foreign nationals from seven Muslim-majority countries (Syria, Iran, Iraq, Yemen, Sudan, Somalia and Yemen) and refugee admissions.
The central question for the appellate court is whether Robart abused his discretion by putting a temporary hold on the travel ban. No court has addressed the constitutionality of the executive order thus far.
The attorney general of Washington state, Bob Ferguson, filed the case and was later joined by the attorney general of Minnesota, Lori Swanson.
The suit is being defended by lawyers at the Civil Division of the Department of Justice in Washington, DC.
The randomly assigned three-judge panel includes Judge William C. Canby Jr, an appointee of President Jimmy Carter; Judge Michelle T. Friedland; who was appointed by President Barack Obama; and Judge Richard R. Clifton, an appointee of President George W. Bush.
When is this hearing?
The appellate court has set an hour-long telephonic oral argument in the case for Tuesday at 6 p.m. ET. It will be available for live streaming through the court's website
Each side will get 30 minutes to make their case.
What are the states saying?
On Monday attorneys for the states that filed the lawsuit submitted their brief urging the appellate court to keep the travel ban suspension in place.
The states say that the temporary restraining order should remain in place because the President had "unleashed chaos" by signing the order.
They also argue that the government's claim -- that it would be "irreparably harmed" by keeping Robart's temporary suspension order in place while the case proceeds to the merits -- doesn't make any sense.
To accept DOJ's position, they argue, "would mean that until the (Executive) Order was issued, Defendants were suffering some, unspecified, ongoing irreparable harm. That makes no sense. ...Preserving the status quo against sudden disruption is often in the interest of all parties."
What is the Trump administration's argument?
The government submitted its own brief in response Monday evening.
DOJ continues to emphasize that the states do not have the ability to sue in this case and a district court judge does not have the right to second-guess the President's national security judgment in the immigration context.
But the government also raised a fallback argument in its latest court filing -- suggesting if the appellate court is inclined to uphold the Seattle district court's decision, then it must at least limit it to the class of people who have been previously admitted to the US -- like someone traveling on a student visa. In the government's view, aliens outside of the US who have never stepped foot on US soil have no constitutional right to enter the US.
What happens next?
The judges have a number of different options at their disposal to resolve this case, but it is unlikely that they would rule on whether the ban is constitutional (since that is not the question before them) -- the central issue is whether the executive order should remain suspended for now.
For example, the judges could dismiss DOJ's request for a stay of Robart's decision because, as the government acknowledges, temporary restraining orders are generally not appealable, or they could uphold his ruling -- but under either scenario the suspension of the ban would remain in place while the case moves forward with further scheduled hearings.
Alternatively, the appellate court could find Robart abused his discretion and overreached to include classes of people not protected under the Constitution (e.g., aliens living abroad) -- in which case the travel ban would go back into effect.
After the three-judge panel publishes its decision, the losing party has 14 days to file a petition for rehearing the case by the full appellate court (but is not required to do so in order to get the case in front of the Supreme Court).
Given the high stakes involved in this lawsuit, it is expected that whoever ultimately loses before the Ninth Circuit will most likely appeal to the Supreme Court.
At the moment, there are only eight justices on the court, meaning if there is a 4-4 split then the Ninth Circuit's ruling will be the law of the land.