Have the courts stopped Donald Trump’s order restricting travel?

Partially and temporarily. Over the weekend, federal judges in four states ordered that no one who was en route or had reached the US with a valid visa or green card at the time the executive order was signed could be deported. They did not decide whether Trump’s measures – to suspend travel from seven Muslim-majority countries for 90 days; to suspend the Syrian refugee program indefinitely; to suspend all refugee admissions for 120 days; and to prioritize refugees of minority – were constitutional.

“It’s a first step,” said Lee Gelernt, deputy director of the immigrants rights project for the American Civil Liberties Union. “Anybody who reached US soil and was not allowed to enter because of the executive order, none of them can be removed from the US while the judge determines the ultimate legality of the order.”

In New York, Judge Ann Donnelly also ordered the government to provide a list of names of people affected by the order. She did not order that people detained in airports be released.

During an emergency hearing Saturday night, she pressed the government for answers about how allowing people who had been vetted to stay would cause “irrevocable harm” to the US. Her eventual decision agreed with the plaintiffs, that returning detained people home could cause such harm, potentially threatening visa-holders’ lives.

Donnelly’s ruling is “the baseline”, Gelernt said, for setting up a legal argument that Trump’s order causes actual harm and unreasonable arguments behind it. Her ruling applied nationwide, to the entire class of people who had already been vetted and were in transit or arrived in the US.

Rulings in Massachusetts, Virginia and Washington differed slightly from Donnelly’s order. In Boston, a judge ordered agents to release detained people and to halt deportations, though only at Logan International. In Alexandria, a judge ruled in favor only of lawful permanent residents – green card holders. In Seattle, a judge’s ruling was limited to two individuals. Attorneys were advising people with green cards to try to redirect their flights into Boston.

Donnelly gave the government two weeks to put together their arguments and scheduled a 21 February hearing. Hearings will proceed at her Brooklyn courtroom, and in Boston, Seattle and Alexandria, and each of the judges will be asked to rule whether the measures are lawful. The Trump administration may appeal the decisions to appellate courts.

Attorney generals in New York and Washington state have called the order unconstitutional and are likely to sue. Lawyers for the ACLU, Council of American-Islamic Relations, National Immigration Law Center and detained travelers are all parties to current suits.

Has the government complied?

Partially. The Department of Homeland Security said in a statement that it would comply with the court orders, but that it would also enforce Trump’s actions going forward, ie for people who had not yet boarded planes.

Detained people were gradually released from airports around the US, but reports proliferated of confusion and apparent defiance of the court orders. At Dulles airport in Virginia, four members of Congress and several volunteer attorneys said that they were denied access to detained travelers on Sunday.

Becca Heller, the director of the International Refugee Assistance Project, told reporters that “rogue” agents were still trying to coerce travelers into signing away their green cards, while “good Samaritan” agents were trying to help lawyers. Gelernt asked for people’s help to document incidents of noncompliance, which could lead to a contempt of court charge. “I think we’re a long way from that,” he said, “but the judge will certainly want to know if her orders are not being complied with.”

One of the congressman, Don Beyer warned that defiance could lead to an extremely dangerous scenario: a “constitutional crisis” in which federal agents refused to respect the judicial branch as a co-equal power. As of Monday, it remained unclear whether confusion, malice or both was behind the reports of noncompliance or extralegal action.

Where do the cases go next?

The Trump administration has yet to appeal or submit its arguments, and in court on Saturday night the lawyers defending it were visibly unsure what to say. “This has unfolded with such speed that we haven’t had an opportunity to address the issues, the important legal issues,” attorney Susan Riley told the court.

If and when the White House defends its executive order, judges will start to weigh the extent of president’s broad powers in immigration. Courts have historically deferred to the president on immigration, and Trump has hinged his powers on a section of the US code that says:

whenever the president finds the entry of any aliens or class of aliens … would be detrimental to the interests of the United States, he may by proclamation … suspend the entry of all aliens or any class of aliens as immigrants or nonimmigrants, or impose on the entry of aliens any restrictions he may deem to be appropriate.”

But another, later law forbids discrimination for visas, saying: “No person shall receive any preference or priority or be discriminated against in the issuance of an immigrant visa because of the person’s race, sex, nationality, place of birth or place of residence.”

The supreme court has never resolved the gray area in these seemingly contradictory laws, nor taken on an immigration case with religion as a major factor. Last year the justices deadlocked 4-4 when trying to decide the extent of Barack Obama’s authority to shield undocumented people from deportation, and they released no inkling of their arguments.

What are the issues at stake?

The New York plaintiffs did not argue on Saturday that Trump’s orders violated the first amendment’s guarantee of freedom of religion. But challenges are expected to this equal-protections clause, bolstered by Trump’s explicit preference for Christian migrants. Last week Trump said he would prioritize Christians, which a former Yale Law School dean called “blatantly unconstitutional”.

David Strauss, a professor at the University of Chicago School of Law, said that this establishment clause may be the strongest claim against the order. “You’re spending government resources to favor one religion over another,” he said, meaning a wide range of people or institutions could have standing to sue.

In the past, the supreme court has allowed discriminatory immigration practices. Trump’s order may have their closest parallel in the 19th century Chinese Exclusion Act, which was ruled constitutional but whose arguments were later abandoned, and the 1940s Japanese internment camps, also found constitutional at the time. Trump’s order is far more sweeping, however, and suits will argue they are premised on religion, raising new questions for the courts.

Around the country, lawyers have also filed complaints that say the order violates the right to due process, arguing that legal residents have been detained arbitrarily and without cause. The White House has argued, at least in the press, that the order is “a matter of national security”, but has yet to put forward an argument in court about how thousands of students, doctors, children and other visa-holders could reasonably constitute a threat.

Strauss said these claims would be more difficult to win, because of the president’s broad authority, but he said it would be far from impossible to convince a judge that the order is unlawfully “arbitrary and capricious”.

Government, he added, “should not be a personal fiefdom of the person who happens to be in the White House”. Strauss said that he was particularly disturbed that the order “expresses a kind of contempt for law”.

The White House insisted on Monday that the court cases do not affect the order. “The action never intended to deport people,” spokesman Sean Spicer said on Monday. “All of the enforcement of action is in place.”

Does this affect the vacant supreme court seat?

Yes. Trump has already advanced his plans to nominate a justice. The legal fight over Trump’s travel ban raises the immediate stakes for placing a ninth justice on the bench, in the event of a close case. Only a handful of Republican senators have criticized the order, Democrats have hinted that they want to block Trump’s pick, and even Mitch McConnell, the majority leader, said over the weekend that the courts should have authority over Trump’s executive orders.

For years the nominating process has become more and more political, culminating in the refusal by a Republican-controlled Senate even to grant a hearing to Obama’s nominee, Merrick Garland, last year. Even if Trump can bring a justice to the court. there is no guarantee that the court would swing 5-4 in his favor.