What's next in legal battle over Trump's immigration ban

President Trump's executive order temporarily suspending the U.S. refugee program and immigration from seven predominantly Muslim countries unleashed chaos at U.S. airports, his firing of the acting attorney general for refusing to enforce the order and a flood of emergency lawsuits from Los Angeles to Boston.

But the larger fight over the legality of the president's order has just begun.

Immigration advocates, civil rights organizations and Democratic attorneys general are filing lawsuits to permanently halt Trump's order. Some argue that it discriminates against constitutional protections for freedom of religion, others argue that it violates a federal law that prohibits discrimination against immigrants based on their country of origin.

The Trump administration says it has complied with rulings issued by federal judges to protect immigrants who were improperly detained or caught up in the chaotic rollout of the order. But administration officials say it is legal and will hold up to judicial scrutiny. "It's fully legal," White House press secretary Sean Spicer said Tuesday.

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At issue is Trump's order that halts the U.S. refugee program for 120 days and bars for 90 days most legal immigration from seven majority Muslim countries with close ties to terrorism: Libya, Iran, Iraq, Somalia, Sudan, Syria and Yemen. The ban on Syrian immigrants is indefinite. Trump says the move is necessary to give authorities time to develop "extreme vetting" measures to ensure that terrorists don't sneak in through those legal immigration channels.

Here's where the legal battle stands now:

Emergency court hearings

Immediately after Trump signed the order on Friday evening, U.S. Customs and Border Protection (CBP) agents started detaining and deporting immigrants who were arriving at U.S. airports.

That prompted a swift response from the American Civil Liberties Union, the National Immigration Law Center and other immigration advocacy and civil rights groups. Those attorneys convinced a federal judge in New York City to issue an emergency, nationwide stay on Saturday night, halting CBP from deporting any other people covered by Trump's ban.

Other judges soon joined in. A judge in Alexandria, Va., ordered CBP on Saturday to begin allowing people being detained at Washington Dulles International Airport to make contact with attorneys. A two-judge panel in Boston then issued a late-night ruling ordering CBP to stop enforcing Trump's order and to release anybody who was awaiting additional screening at Logan International Airport.

On Sunday, a federal judge in Los Angeles ordered the federal government to return an Iranian man who was deported to Tehran from Los Angeles International Airport under Trump's order. And a judge in Seattle prohibited CBP from deporting two people detained at Seattle-Tacoma International Airport.

Homeland Security exceptions

Travelers around the world were confused by Trump's order, as many legal immigrants were prohibited from boarding their U.S.-bound flights and others were simply unsure whether they should try and fly back to the U.S.

CBP Acting Commissioner Kevin McAleenan on Tuesday blamed those holdups partly on airlines that "over-interpreted our orders." He said all of the confusion was cleared up by the end of the weekend and that people were being processed quickly and legally.

He said 1,060 green card holders have been granted waivers to enter the U.S. after additional screening. McAleenan said the department will also allow 872 people who were granted refugee status to enter the country this week.

Broader legal challenges

With most of the emergency cases from the weekend resolved, the next phase will be legal challenges seeking to overturn Trump's order.

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There won't be any central case attacking the order, but a variety of lawsuits using different legal arguments. "It's probably important to have different courts around the country weighing in so you don’t have the president just trying to dismiss any one holding as being inconsequential," said Matt Adams, legal director of the Northwest Immigrant Rights Project, which is leading one of the lawsuits.

Adams' lawsuit was filed in Seattle on behalf of three parents legally living in the U.S. who are now restricted from bringing their children from Somalia, Syria and Yemen. Another lawsuit filed in Michigan claims Trump's order discriminates against Muslims and violates constitutional protections for the free exercise of religion.

Lawyers also will use followup hearings from the emergency rulings issued over the weekend to try and overturn the entire order. New York Attorney General Eric Schneiderman, a Democrat, joined the lawsuit in his state, and Virginia Attorney General Mark Herring, also a Democrat, joined the lawsuit in his state. A total of 16 attorneys general — all Democrats — issued a joint statement vowing to fight Trump's order.

Trump's defense

For a short time on Tuesday, it was the policy of the Department of Justice that Trump's order was not lawful and its attorneys would not defend it.

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That came from Acting Attorney General Sally Yates, an Obama administration holdover. Trump quickly fired her and appointed Dana Boente, the U.S. attorney for the Eastern District of Virginia, to serve as acting attorney general until his nominee, Sen. Jeff Sessions, R-Ala., can be confirmed by the Senate.

On Tuesday, Spicer said Yates' own department had found the order to be legal and the administration is confident it will be upheld in court.

"Ms. Yates failed to enforce a legal order, approved by the Department of Justice's Office of Legal Counsel and designed to protect the citizens of the United States," Spicer said. "Calling for tougher vetting for individuals traveling from seven nations is not extreme. It is reasonable and necessary to protect our country."