A legal showdown on the border between the US and Texas: What to Know

The Biden administration is suing the state of Texas over a new state law that would empower state and local police officers to arrest migrants who cross from Mexico without authorization.

On Thursday, a federal court in Austin heard three hours of arguments over whether to halt the implementation of the law, which is set to go into effect March 5.

The case has far-reaching implications for the future of immigration law and border enforcement and has been closely watched across the country. It comes amid fierce political fighting between the parties — and within them — over how to handle illegal immigration and follows the impeachment by House Republicans of the secretary of homeland security, and the failure of a bipartisan Senate deal to bolster security at the border.

Texas has argued that its law is necessary to deter migrants from crossing illegally, as has happened in record numbers over the past year. The Biden administration argues that the law conflicts with federal law and violates the U.S. Constitution, which gives the federal government authority over immigration matters.

The judge hearing the case, David A. Ezra of the Western District of Texas, was appointed to the bench by President Ronald Reagan. He had frequent questions, particularly when the lawyer representing the Texas attorney general was speaking, and appeared skeptical of the law.

“Let’s say for the purpose of argument that I agree with you,” Ezra told the state’s lawyer, Ryan Walters. California might then want to pass its own immigration and deportation law, he said. Maybe then Maine would follow, he added, and then other states.

“That turns us from the United States of America into a confederation of states,” Ezra said. “What a nightmare.”

The law passed by the Texas Legislature, known as Senate Bill 4, makes it a crime to cross into Texas from a foreign country anywhere other than a legal port of entry, usually the international bridges from Mexico.

Lawyers for the Biden administration argue that the Texas law conflicts with numerous federal laws passed by Congress that provide for a process for handling immigration proceedings and deportations.

The fight over the law is likely to end up before the U.S. Supreme Court, legal experts have said. If so, it will give the 6-3 conservative majority a chance to revisit a 2012 case stemming from Arizona’s attempt to take on immigration enforcement responsibilities. That case, Arizona v. United States, was narrowly decided in favor of the power of the federal government to set immigration policy.