AUSTIN, Texas (AP) — For two years, Texas has pushed boundaries on the U.S.-Mexico border: Busing migrants across America, jailing thousands for trespass and stringing razor wire along the Rio Grande.

In a new challenge to the federal government’s authority over immigration, Texas lawmakers on Tuesday night gave final approval to a bill that would allow police to arrest migrants who enter the country illegally and let local judges order them to leave the country.

The bill, which Republican Gov. Greg Abbott is expected to sign, would become one of the nation’s strictest immigration laws if allowed to take effect.

In a rare moment of GOP dissension, one powerful Republican state senator opposed the bill, saying it goes too far. Emotions also ran high in the Texas House, where Democrats spent hours condemning the measure but failed to weaken it before it passed along party lines 83-61. It cleared the Texas Senate last week.

Here’s a look at the proposal:

WHAT WOULD THE NEW LAW DO?

Texas arresting migrants is not new. Within six months of President Joe Biden taking office, Texas troopers began making agreements with border landowners and arresting migrants who crossed their properties for trespassing.

But the new law would empower all police in Texas — including officers hundreds of miles (kilometers) from the border — to arrest migrants suspected of illegally entering the country. The offense would be a misdemeanor and a judge could order the defendant to leave the country.

Critics say the law could lead to racial profiling or the wrongful arrest of U.S. citizens and immigrants who are in the country legally. Democrats also said it would make immigrant crime victims afraid to contact police.

One of the Republicans carrying the bill, state Rep. David Spiller, said the law would not apply to residents who have been in the country for more than two years. He defended the bill as having sufficient guardrails and said it would mostly be applied near the border.

“This is not, ‘Round up everyone who is here illegally and ship them back to Mexico,’” Spiller told a legislative committee last week.

Steven McCraw, the director of the Texas Department of Public Safety, told lawmakers that it would be “almost impossible” for the law to be enforced in any county that was not directly along Texas’ 1,200-mile (1,900-kilometer) border with Mexico, because an officer would need evidence that a migrant had crossed illegally.

“It’d be a stretch,” McCraw said.

TESTING IMMIGRATION AUTHORITY

Legal experts and immigrant rights groups have railed against the Texas bill as a clear conflict with the U.S. government’s authority to regulate immigration.

“Since when does a state deport individuals?” Democratic state Rep. Victoria Neave Criado said. “That’s not a power that states have. That’s a power that the federal government has.”

She and other Democrats say the state wants the U.S. Supreme Court’s new conservative majority to revisit a 2012 ruling that struck down key provisions of an Arizona immigration law. At the time, Justice Anthony Kennedy said Arizona may have “understandable frustrations” with immigrants who are in the country illegally but can’t pursue policies that “undermine federal law.”

Spiller has denied wanting to challenge the Arizona decision. But the bill has given pause to at least one of his fellow Republicans.

State Sen. Brian Birdwell, an Army veteran who was injured at the Pentagon during the Sept. 11, 2001, attacks, was the lone Republican to vote no, saying the law would usurp powers given to the federal government. It was a rare moment of opposition in the Texas Senate, where Republicans typically vote in lockstep.

“For the short-term messaging gain between our two chambers during this election season, we are setting a terrible precedent for the future by invalidating our obedience and faithfulness to our Constitution,” Birdwell said.

TEXAS’ MASSIVE BORDER OPERATION

In his third term as Texas governor, Abbott has made increasingly aggressive measures on the Texas-Mexico border a centerpiece of his administration.

In addition to giving police new arrest powers, Texas Republicans are also on track to approve $1.5 billion to continue building more border wall. Texas has also gone to court in recent months to keep a floating barrier on the Rio Grande and to prevent Border Patrol agents from cutting razor wire.

The efforts have not halted crossings, which have remained unusually high. Illegal crossings did fall in October, a rare piece of welcome news for a White House that has been criticized by the right and left for its immigration policies.