Trump's immigration order: legal headache

US president Donald Trump

What you need to know:

  • Trump's decree slapped a blanket ban on entry for nationals of seven predominantly Muslim countries for 90 days and barred all refugees for 120 days. Refugees from Syria were blocked indefinitely. But a federal judge issued a temporary nationwide suspension of the president's order, which the US government swiftly appealed.

Washington. Donald Trump's executive order on immigration has legal experts grappling with a key question: how broad is the US president's reach when it comes to shaping migration policy?

Trump's decree slapped a blanket ban on entry for nationals of seven predominantly Muslim countries for 90 days and barred all refugees for 120 days. Refugees from Syria were blocked indefinitely. But a federal judge issued a temporary nationwide suspension of the president's order, which the US government swiftly appealed.

The ultimate ruling in the case could clear confusion regarding Trump's executive reach and leave a lasting legal impact. Here is a look at the process: Who will decide?

There is a chance the case will go all the way to the Supreme Court, the nation's top bench that is the final interpreter of US constitutional law. For now, all eyes are on the Ninth Circuit Court of Appeals, based in San Francisco, as it weighs the order temporarily halting the ban nationwide, issued by Seattle federal judge James Robart.

A hearing before three judges on the court - two of whom were appointed by Democratic presidents, and one by a Republican - took place Tuesday and a decision could come as early as Wednesday. As a federal judge, Robart's ruling has nationwide validity. While several other federal judges had previously issued rulings on narrow aspects of Trump's executive order, his was the first to address it as a whole. Who is involved? The Trump administration has challenged Robart's ruling by filing an emergency motion with the Ninth Circuit Court of Appeals saying that suspending the ban harms national security.

The primary plaintiffs are two Democratic-leaning states that border Canada: Washington, where Robart sits, and Minnesota. They were backed in a court brief filed by 16 state attorneys general. A number of groups have filed briefs backing the states' efforts, including the American Civil Liberties Union, the Southern Poverty Law Center - which monitors extremism in the US - and the HIAS refugee protection organisation. (AFP)