El Paso County Sues Texas in a Bid to Block New Migrant Arrest Law

El Paso County and two immigrant rights groups sued Texas officials on Tuesday to challenge a sweeping new law that allows state and local police to arrest migrants who cross from Mexico, setting up a legal showdown over federal immigration policies.

The federal lawsuit came a day after Gov. Greg Abbott signed the bill, which he called “so extreme” that he believed it would drive migrants away from Texas. Civil and immigrant rights groups and Democratic officials said the law violated the Constitution and invited racial profiling of Hispanic citizens in Texas.

In the suit, El Paso County and the two nonprofit groups argue that the state law should be struck down in its entirety because the federal government has exclusive authority over immigration matters.

The suit, filed in federal court in Austin, names as defendants the Texas Department of Public Safety, whose officers would be newly empowered to make arrests under the law, and the district attorney for El Paso, Bill Hicks, whose office would prosecute the offenses. The American Civil Liberties Union is representing the plaintiffs.

Mr. Abbott, a Republican, anticipated such a challenge. He has presented the law as a necessary reaction to what he has called the failure of President Biden to enforce existing federal law against crossing into the United States without authorization.

A spokesman for Mr. Abbott did not immediately reply to a request for comment on the lawsuit, nor did Mr. Hicks, who has said his office would not prioritize migrant arrests. A spokesman for the Department of Public Safety referred questions to Mr. Abbott’s office.

Republicans have blamed President Biden for the surge of migrants who have entered the United States in record numbers the past three years, a trend that has become a political liability for him as he seeks re-election.

Over the last two years, Mr. Abbott, a third-term Republican, has steadily ratcheted up a strategy of state border enforcement, challenging the Biden administration to take Texas to court over it. The governor and the Republican-controlled state legislature have increasingly been at odds with the municipal governments of Texas cities, where Democrats are mostly in charge. Mr. Abbott has sparred publicly with mayors and urban district attorneys in Texas over a range of policies, including coronavirus restrictions, enforcement of abortion bans and police accountability.

The top officials in El Paso County, which includes the city of El Paso, are Democrats. Before the law was signed, the sheriff’s office in El Paso, a county agency, said that it opposed the new law’s approach and would not make arrests under the law.

Mr. Abbott has tried to put pressure on Democratic leaders in several of the nation’s largest cities outside Texas by busing tens of thousands of migrants from the Texas border to destinations like New York, Washington, Los Angeles and Chicago.

The new state law, known as Senate Bill 4 and scheduled to take effect in March, makes it a misdemeanor to cross into Texas from Mexico without using an authorized port of entry. A person arrested under the law could be ordered by a court to return to Mexico or face prosecution if they did not agree to go. A second unauthorized crossing would be a felony.

A claim of asylum would not shield a migrant from arrest or prosecution for illegal entry under the new state law unless asylum had already been granted. But the process of reviewing an asylum claim often takes years.

“It’s likely that it will create a dragnet that ensnares not only undocumented immigrants, but also Americans and legal permanent residents,” said Representative Joaquin Castro, Democrat of San Antonio, who has asked the Justice Department to intervene to stop the law from taking effect.

According to the lawsuit, the Texas law is an attempt at “grasping control over immigration from the federal government and depriving people subject to that system of all of the federal rights and due process that Congress provided to them.”

Mr. Abbott said on Monday that while he believed the law would withstand legal scrutiny, it presented an opportunity for the federal courts, and ultimately the Supreme Court, to reconsider a 2012 decision, Arizona v. United States, that narrowly ruled in favor of the federal government and against state efforts to enact their own immigration laws.

In the complaint, lawyers for El Paso County estimated that the law could result in 8,000 additional arrests each year, creating steep costs for county courts and jails and upending the relationship between the county government and its large immigrant community. The county, which has 869,000 residents, estimated that new jail facilities would cost more than $160 million, along with another $24 million each year to house the migrants arrested under the law.

The two nonprofit groups that have joined with the county in filing the suit — Las Americas Immigrant Advocacy Center and American Gateways, both of which provide legal services to migrants — said the law would harm their ability to assist migrants, including those seeking asylum.

“Governor Abbott’s efforts to circumvent the federal immigration system and deny people the right to due process is not only unconstitutional, but also dangerously prone to error,” Anand Balakrishnan, senior staff attorney at the A.C.L.U.’s Immigrants’ Rights Project, said in a statement.