A US appeal court has handed a resounding victory to Washington and Minnesota in their challenge to Donald Trump's travel ban, finding unanimously that a lower court ruling suspending its enforcement should stay in place while the case continues.
Here is a summary of the legal issues in the 9th Circuit Court of Appeals' ruling - and what comes next.
For now, it means refugees and people from seven majority-Muslim nations identified in the president's surprise January 27 executive order can continue entering the country.
Travellers from those countries will not be detained or put back on planes heading overseas and there probably will not be more protests jamming US airports as there were after Mr Trump issued the surprise order.
But the executive order is not dead either, it just is not being enforced while the courts debate its legality.
The government has 14 days to ask the court to reconsider Thursday's decision and it could also file an emergency appeal with the US Supreme Court, which would go to Justice Anthony Kennedy for referral to the rest of the court.
Rory Little, a former Supreme Court clerk who teaches at the University of California Hastings College of the Law, does not think that is such a good idea.
In addition to seeking to overturn a reasoned decision, he said, Mr Trump would be facing Chief Justice John Roberts, who just wrote an annual report in which he raved about his District Court judges.
The president repeatedly insulted the Seattle judge who ruled against him, in addition to the appeal judges who followed suit.
"I think Kennedy and Roberts are seething about the president insulting their judges," Mr Little said.
"If they go to the US Supreme Court, they risk getting a serious adverse ruling."
There have been, in effect, two items before the court: the government's appeal of the lower judge's ruling and its motion to put that ruling on hold pending the appeal.
On Thursday, the panel denied the motion for stay and set a briefing schedule for fuller arguments on the merits of the appeal.
That prompted some confusion among those watching the case, many of whom expected it to be returned to the Seattle court.
Washington's lawyer, state solicitor general Noah Purcell, wrote to the Seattle court's clerk late on Thursday to note the state would not be making an expected court filing because of the new appellate briefing schedule.
Barring an immediate appeal to the Supreme Court, the government's opening brief is due on March 3, with the states' filing due on March 24.
In denying the motion for stay, the court said it was considering whether the administration was likely to win its appeal, whether suspending the travel ban had harmed the government, and whether the public interest favoured granting the stay or rejecting it.
The judges agreed that the lower court's ruling was appealable - the only question on which the states lost.
They rejected the Justice Department's argument that the states lacked standing to sue, noting that some faculty members at state universities were unable to travel, for example.
But most forcibly, they rejected the DOJ's notion that the president has nearly unlimited authority over immigration decisions.
"There is no precedent to support this claimed unreviewability, which runs contrary to the fundamental structure of our constitutional democracy," the opinion said.
Based on what they know so far, Mr Trump's executive order poses some serious constitutional concerns, the panel said.
For example, the government has not shown that it complies with due process, by giving those affected notice or a hearing before restricting their ability to travel.
While the government insisted that most or all those affected do not have such rights, the court disagreed, saying the protections of the Fifth Amendment's due process clause are not limited to US citizens.
And while White House counsel Donald McGahn issued guidance days after the executive order saying it did not apply to legal permanent residents of the US, some of whom had been caught up in the travel ban, that guidance was of little use, the court wrote.
Many conservatives condemned the ruling and some law professors criticised various aspects of it, including its lack of analysis regarding a law giving the president power to suspend entry of "any class of aliens" when he finds their entry "would be detrimental" to the country.
Republican senator Tom Cotton of Arkansas called the decision misguided and wrote off the court it came from as "the most notoriously left-wing court in America".
While the 9th Circuit certainly has a lefty reputation, based in part on the long tenure of the many liberal judges that Democratic president Jimmy Carter appointed, legal scholars say the label is less deserved than it used to be.
Two of the judges on the panel that made the ruling are Democratic appointees, while one, Judge Richard Clifton, was appointed by George W Bush.
Carl Tobias, a law professor at the University of Richmond Law School, said Judge Clifton's decision to join the opinion should allay any concerns that it was motivated by politics instead of the law.
That should make the government think twice before going to the Supreme Court, he said.
"I don't think they're going to be well received at the Supreme Court for all kinds of reasons, but mainly because this is a reasonable decision. The precedents are there, they've weighed the issues, and even Clifton signed it."