The American Civil Liberties Union filed a lawsuit on Wednesday challenging President Biden’s decision to shut down the southern border to nearly all migrants seeking asylum in the United States.
The action is the first legal challenge to an order that the Biden administration hopes will decrease the number of illegal border crossings and neutralize one of the president’s most serious political vulnerabilities.
In a statement, the A.C.L.U. said the asylum ban, which went into effect one week ago, violated legal protections for people seeking protection in the United States.
Mr. Biden’s order blocked access to asylum for migrants who cross the U.S.-Mexico border without authorization. President Donald J. Trump tried to cut off migration in a similar way in 2018, but the move was blocked in federal court.
“The asylum statute could not be clearer: that one must be able to seek protection regardless of where they enter the country, which is why the courts struck down Trump’s near-identical asylum ban and is undoubtedly why the Biden administration has acknowledged it may not be able to do this by unilateral executive fiat,” said Lee Gelernt, a lawyer with the A.C.L.U. who has challenged several immigration policies under the Biden and Trump administrations.
The lawsuit, which was also joined by groups including the National Immigrant Justice Center and the Center for Gender and Refugee Studies, was filed in federal court in Washington, D.C. It takes issue with the executive action broadly, as well as several more narrow restrictions that the administration has imposed, such as giving migrants only four hours to find a lawyer if they want to argue that they be granted an exception to the asylum ban.
The restrictions would lift only when the number of illegal crossings drops to fewer than 1,500 for seven days in a row and remains that way for two weeks. The numbers have not been that low in years; in December, there were some 10,000 illegal crossings every day. More recently, the figures have hovered around 3,000 crossings per day.
There are exceptions to the order, including for unaccompanied children and victims of human trafficking. People can also schedule an appointment to claim asylum using a Customs and Border Protection app.
Migrants who say they are fearful of returning can still ask for protection in the United States, but they will have to volunteer such claims without being asked, a practice known as the shout test. They will also have to use programs other than asylum that have a much higher bar and that most people will not qualify for.
But a vast number of people seeking asylum cross illegally and then seek out border agents to turn themselves in, knowing that in many cases they would be released into the United States to await court appearances that can take years to come up.
Mr. Biden’s order aims to stop that by allowing border agents to turn back migrants more quickly, suspending longtime guarantees that give anyone who steps onto U.S. soil the right to ask for safe haven.
Immigrant advocates and some congressional Democrats have criticized the effort.
“This asylum ban will fail to address the challenges at our border, just as it did under the Trump administration,” said Senator Alex Padilla, Democrat of California. “It will lead to people with legitimate asylum claims being prevented from seeking safety and returned to harm.”
Republicans have used illegal immigration as an attack line against Mr. Biden, even as some have tried to thwart his efforts to address the problems. In February, egged on by Mr. Trump, Republicans blocked bipartisan legislation that had some of the most significant border restrictions Congress had considered in years.