Saying that America’s border under the Biden administration has become “little more than a speedbump for aliens flooding into the country,” a federal judge in Florida has blocked a new policy allowing the federal government to release asylum-seeking migrants pending subsequent immigration hearings.

The policy — known as Parole+ATD — allowed Immigration and Customs Enforcement to release migrants into the country if they cross the border illegally, with the requirement that they report to ICE by using traceable cell phones or by wearing ankle monitors. 

Judge T. Kent Wetherell of the Northern District of Florida ruled on Wednesday that the policy violated the Immigration and Nationality Act of 1965, which states that “the alien ‘shall be detained’ pending a final determination of asylum or credible fear of persecution.”

Florida’s attorney general, Ashley Moody, brought the lawsuit to federal court in January, citing the drain on public resources that accompanies unlimited immigration flows and the threat of fentanyl trafficking. 

“The Biden administration is releasing tens of thousands of migrants at the border every month. Many of these migrants are arriving or will arrive in Florida, harming the state’s quasi-sovereign interests and forcing it to incur millions of dollars in expenses,” the lawsuit said. 

In his ruling, Judge Wetherell wrote that the administration “effectively turned the Southwest Border into a meaningless line in the sand and little more than a speedbump for aliens flooding into the country.” He added that “there is nothing inherently inhumane or cruel about detaining aliens pending completion of their immigration proceedings.”

The policy director for the American Immigration Council, Aaron Reichlin-Melnick, said the ruling is likely to lead to a backlog of immigrants stuck in detention centers at or near the border, such as occurred frequently during the Trump administration and the early days of Mr. Biden’s tenure.

In 2019, overcrowded detention centers at the border became a cause celebre for Democratic members of Congress and presidential candidates — including the current vice president — who traveled to the southern border to decry the policies of President Trump. Mr. Reichlin-Melnick said the judge’s ruling could lead to a repeat of those overcrowded conditions.

“If the Border Patrol doesn’t have the ability to use Parole + ATD, it’s going to severely impact the agency’s ability to get people out of border detention centers,” Mr. Reichlin-Melnick said on Twitter.

According to the Center for Immigration Studies, 338,000 migrants were released from border patrol custody under Parole+ATD and allowed into the United States in 2022. Since the beginning of this year, the Customs and Border Patrol has released another 290,000 migrants.

The ruling comes as President Biden is weighing a number of changes to his immigration policies ahead of a likely re-election announcement. According to the New York Times, Mr. Biden is considering reinstating the family detention policy that he railed against during the presidential campaign in 2020. 

The homeland security secretary, Alejandro Mayorkas, told CNN’s Christiane Amanpour that “no decision has been made” with respect to detaining or separating families.