By Daniel Wiessner and Ted Hesson
(Reuters) -A U.S. appeals court has kept on hold a Republican-backed Texas law that would let state authorities arrest and prosecute people suspected of illegally crossing the U.S.-Mexico border - a statute that President Joe Biden's administration has argued intrudes on the authority of the federal government.
In a 2-1 ruling late on Tuesday, a panel of the New Orleans-based 5th U.S. Circuit Court of Appeals denied a request by Texas to let the law take effect while the state's appeal of a judge's ruling blocking it plays out.
The law, formally called S.B. 4, has become a flashpoint in a broader battle between Texas and the Biden administration over border security and immigration. It would make it a state crime to illegally enter or re-enter Texas from a foreign country and would empower state judges to order that violators leave the United States, with prison sentences up to 20 years for those who refuse to comply.
The 5th Circuit panel's action was the latest of three rapid-fire rulings on the status of the law. The Supreme Court last week had let it take effect, but the 5th Circuit panel hours later restored U.S. District Judge David Ezra's February injunction blocking enforcement.
Ezra, based in Austin, cited a 2012 U.S. Supreme Court ruling involving an Arizona law that held that states cannot adopt immigration enforcement measures that clash with federal law.
The 5th Circuit panel is scheduled to hear arguments on the merits of the state's appeal on April 3.
Circuit Judge Andrew Oldham, an appointee of Republican former President Donald Trump who dissented in Tuesday's decision, predicted that the panel would uphold the ruling blocking S.B. 4 over his objections.
The decision "means that we'll likely never know how Texas's state courts and its state law-enforcement officers would have implemented S.B. 4," Oldham wrote in his dissenting opinion.
The lawsuit, filed in January, argued that the measure violates the U.S. Constitution and federal law by interfering with the U.S. government's power to regulate immigration as well as running afoul of the 2012 Supreme Court decision.
Biden's administration has said immigration is the exclusive province of the federal government and that the Texas law would upend enforcement of complex U.S. laws that establish procedures for deportation and allow migrants to apply for asylum and other legal status.
'REAL POLICY SOLUTIONS'
Civil rights groups that joined the Biden administration in challenging the law lauded Tuesday's ruling.
"This unconstitutional proposal should never have gotten this far, and we look forward to the courts blocking it permanently so we can get back to discussing real policy solutions," Edna Yang, co-executive director of the group American Gateways, said in a statement.
The U.S. Justice Department and the office of Republican Texas Attorney General Ken Paxton did not immediately respond to requests for comment.
Some local law enforcement officials in Texas said in interviews they were skeptical of the impact the law would have even if the courts do allow it to take effect because of limited resources for enforcement.
"It's really not going to change a lot on the border because of capacity to do more. Everybody's doing all they can right now. Fortunately the federal government is there doing their part in most places," said Skylor Hearn, executive director of the Sheriffs' Association of Texas, whose membership includes most of the state's 254 counties.
Immigration and security along the border with Mexico are hot topics for voters ahead of the Nov. 5 U.S. election in which the Democratic president is seeking a second term in office. Trump, the Republican candidate challenging Biden, pursed restrictive immigration policies during his presidency.
Texas Governor Greg Abbott, a fierce Republican critic of Biden's immigration policies, signed the law in December, saying it was necessary to address record levels of illegal entries, which Republicans have said drain states resources and threaten public safety. The Border Patrol was averaging around 3,800 migrant arrests per day border-wide over the past week, according to internal government data shared with Reuters.
The Biden administration has said interference from Texas and other states only compounds the problem at the border.
It and other critics of the Texas law have said that migrants who cross the border already can be charged with illegal entry or re-entry under federal laws. Advocates for migrants have said the law could fuel racial profiling by state authorities of people already in Texas.
The challenge to the Texas law is one in a series of legal disputes between Republican state officials and the Biden administration over the state's ability to police the border, including its placement of razor-wire fencing and the installation of a 1,000-foot-long (300 m) floating barrier in the Rio Grande river.