A Sweeping New Immigration Law Takes Effect in Texas

The most aggressive state-level immigration law in the nation went into effect in Texas on Tuesday after the U.S. Supreme Court temporarily sided with Gov. Greg Abbott in his increasingly bitter confrontation with the Biden administration over border policy.

The law makes it a crime for migrants to enter Texas from Mexico without authorization, and creates a process for state courts to order migrants charged with violating the law to return to Mexico, no matter their national origin.

The high court ruled that the law could temporarily go into effect while a federal appeals court further considers whether to override a lower-court ruling that found the Texas measure unconstitutional on a variety of grounds.

“Huge win,” Ken Paxton, the Texas attorney general, said in a statement. Mr. Abbott, the governor, sounded a slightly more cautious note about the Supreme Court’s decision, describing it as “a positive development.”

The U.S. Court of Appeals for the Fifth Circuit said that it would hold oral arguments Wednesday morning on whether the lower-court injunction blocking the law should be allowed to stay in effect while the full appeal is underway.

The sudden clearance for the law to go into effect appeared to catch Texas officials off guard. As of Tuesday evening, no date had been set for enforcement to begin. Two state officials said that the timing was still being discussed and that arrests could begin within days.

By allowing arrests to begin in Texas, even temporarily, the Supreme Court injected a new element of uncertainty to what has already been a divisive national debate over immigration, ensuring that the issue remains a centerpiece of the 2024 race between President Biden and former President Donald J. Trump.

Now, the fate of a migrant arriving in Texas could be vastly different than one arriving in New Mexico or Arizona.

Karine Jean-Pierre, the White House press secretary, said that the Biden administration disagreed with the court’s ruling and that the new law would “sow chaos and confusion at our southern border.”

In a statement, the Mexican government said that it “categorically rejects” any law that allows state or local authorities in the United States to “arrest and return nationals or foreigners to Mexican territory” and that it would not accept deportations made by Texas.

As the Supreme Court’s ruling came down, National Guard troops stationed in the border city of Eagle Pass, as part of Mr. Abbott’s border enforcement efforts, sat in Humvees in a city park that has been taken over by Texas in an attempt to prevent crossings there. Others troops patrolled the waters of the Rio Grande near tall fences topped with razor wire.

Until now, they have only had authority to make trespassing arrests on private land, with the landowner’s permission. There were few signs along the border on Tuesday that the legal landscape had changed.

In any case, there have been few migrant crossings in the area in recent days, officials said, reflecting a sharp overall decline in crossings into the United States from Mexico since a peak in December.

Any new arrests were expected to be primarily conducted by Texas Department of Public Safety officers who have been assigned to the border as part of Mr. Abbott’s border program, known as Operation Lone Star.

Texas officials have said in court filings and interviews that they would focus their enforcement of the law on single men and women observed by officers crossing the Rio Grande from Mexico. Families would be turned over to U.S. Border Patrol agents, as is currently the practice.

“Our focus will be more on single adults, not families,” Lt. Christopher Olivarez, a spokesman for the Texas Department of Public Safety, said in an interview before the Supreme Court’s ruling. “Single men, single women.”

“That’s how we do it right now with criminal trespass,” he added.

For more than two years, state police officers in Texas have already been charging migrants found on private land with criminal trespassing. But the new law would allow them to make arrests anywhere in the state. And any officer is permitted to enforce the new law, empowering sheriffs, county constables and local police officers far from the border to engage in immigration enforcement.

The expansiveness of the law, often referred as Senate Bill 4 or S.B. 4, brought sharp criticism from civil rights and immigrant advocacy groups as well as Texas Democrats. Tempers flared during debate over the law in the State Legislature last year.

“This is a dangerous day for our democracy,” said Representative Armando Walle, a Houston Democrat who strongly objected to the law. “S.B. 4 will not make our border more secure. It will instead spread fear in our communities.”

Anand Balakrishnan, a senior staff attorney at the American Civil Liberties Union, which had sued Texas over the law along with the Biden administration, said the Supreme Court’s decision “threatens the integrity of our nation’s immigration laws and bedrock principles of due process.”

Some county leaders along the border and sheriffs who operate county jails had expressed concern that the new law could lead to their courts and jails being overrun with migrants. A first offense is a misdemeanor under the law. A second offense is a felony.

In a court filing by Texas as part of the federal case, Victor Escalon, a top leader from the state public safety department, said officers would concentrate enforcement in areas near state prison facilities, which have already been used as jails for migrants awaiting trial on trespassing charges.

Mr. Olivarez said in the interview before the Supreme Court ruling that any initial rounds of arrests would probably be limited by the capacity of processing centers in the city of Del Rio and in Jim Hogg County, which were set up to handle trespassing arrests. He said each had space for around 100 migrants during initial court processing.

Mr. Olivarez pointed to a period last summer when large numbers of migrants were crossing and state police officers had to limit the number of arrests they could make at any one time. “We made 30 to 40 arrests within the first hour, and then we had to kind of hold off for the rest of the day because we were at capacity,” he said.

Tensions between the federal government and Texas have played out in several court cases that are focused in and around a park in Eagle Pass known as Shelby Park, where state officers have concentrated many of their enforcement efforts.

In January, the state barred Border Patrol agents from gaining access to the river bank along the park, though federal agents can still use the boat ramp there.

Federal agents have at times cut the concertina wire, placed by Texas National Guard troops along the river bank at Eagle Pass, in order to assist migrants who are trying to climb out of the river. The Supreme Court, in a separate case, sided with the federal government and said the agents could cut the sharp wire when necessary.

Those tensions were not evident along the river on Tuesday afternoon, as federal border agents stood on a pair of U.S. Customs and Border Protection airboats, and two smaller craft belonging to the Texas National Guard stood nearby.

Further north along the river, state troops continued to install new razor wire and fencing to prevent migrants who come ashore, including those who may be legally seeking asylum, from reaching Border Patrol agents and turning themselves in.