The Justice Department moved on Friday to dismiss its Biden-era challenge of an Iowa law that made it a state crime for some undocumented immigrants to enter the state, a victory for Iowa Republicans as the Trump administration pursues an aggressive campaign against illegal immigration.
The short filing submitted by Justice Department lawyers in Federal District Court in Des Moines did not provide any reasoning for seeking the dismissal, and it did not immediately remove judicial blocks on Iowa enforcing its law. A similar filing on Friday sought the dismissal of a Justice Department challenge to an Oklahoma immigration law that had also been blocked.
Justice Department officials did not respond on Friday evening to questions about whether the Iowa filing signaled a broader policy shift on state-level immigration enforcement, which it had opposed during Joseph R. Biden Jr.’s presidency.
Attorney General Brenna Bird of Iowa, whose office has defended her state’s law in court, celebrated the dismissal motion and linked it to President Trump’s approach to immigration.
“When the Biden administration failed to do its job and secure our borders, Iowa stepped up. And we never backed down — even when Biden sued us for it,” Ms. Bird, a Republican, said in a statement. “Today, President Trump, again, proved that he has Iowa’s back and showcased his commitment to Making America Safe Again by dropping Biden’s ridiculous lawsuit.”
Yaakov M. Roth, an acting assistant attorney general, was one of the Justice Department lawyers who asked for the dismissal of the Iowa case. No similar dismissal motion appeared on Friday evening on the public docket for a challenge to a similar Texas law that Mr. Biden’s Justice Department also sued to block.
A federal district judge blocked Iowa from enforcing its law last year in separate challenges from the Justice Department and an immigrant rights group, the Iowa Migrant Movement for Justice. A three-judge panel of the U.S. Court of Appeals for the Eighth Circuit kept in place the injunction in the Justice Department’s challenge in a January ruling. The panel was composed of jurists appointed by Republican presidents.
“As a matter of politics, the new legislation might be defensible,” Judge Stephen Locher, a Biden appointee, wrote when he granted the injunction last year. “As a matter of constitutional law, it is not.”
The American Civil Liberties Union of Iowa, which is representing the Iowa Migrant Movement for Justice in its lawsuit, did not immediately respond to a request for comment.
The fight in Iowa is part of a broader effort by conservative states, including Louisiana, Oklahoma and Texas, to carve out a role in immigration enforcement by creating their own laws. In doing so, they entered legal territory that Mr. Biden’s Justice Department argued should be the exclusive domain of federal officials. The U.S. Supreme Court could ultimately consider the question of whether states can enforce their own immigration laws.
In November, Arizona voters approved a ballot measure that would make it a state crime to enter the state outside official ports of entry or to refuse to comply with orders to leave the United States. That law would not take effect unless the courts allowed another state to enforce a similar law.
Details of the new laws vary from state to state. Iowa’s measure, passed in 2024 by the Republican-controlled Legislature and signed into law by Gov. Kim Reynolds, does not go as far as some others.
The Iowa legislation makes it a misdemeanor to enter the state if a person was previously deported, denied entry to the United States or left the country while facing a deportation order. In some cases, including if a person had certain prior convictions, the state crime would become a felony. Iowa police officers would not be allowed to make arrests under the legislation at schools, places of worship or health care facilities.
The Oklahoma law, known as H.B. 4156 and also backed by Republicans, would make it a crime to enter the state without legal authorization to be in the United States. The office of Gentner Drummond, the Oklahoma attorney general, celebrated the dismissal request on Friday.
“The nation’s porous southern border has been a serious threat to the safety and security of Oklahomans,” Mr. Drummond said in a statement. “The sooner we can finally enforce H.B. 4156, the better.”
