'Uncharted': Texas argues in support of sweeping immigration law amid scrutiny in court

A federal appeals court on Wednesday heard arguments about whether to temporarily block the state of Texas from enacting a sweeping and controversial new immigration law while further litigation plays out.

The state's Senate Bill 4, also known as SB4, allows Texas authorities to arrest anyone suspected of being an unauthorized migrant and order them to leave the U.S. or face prison time, law enforcement action that is typically carried out by federal agents.

The law also gives judges the power to order migrants to be transported to a port of entry and returned to Mexico regardless of their country of origin.

While Gov. Greg Abbott, a Republican, calls SB4 necessary to address the White House's "dangerous" border policies, the Biden administration has warned that it will "throw immigration enforcement into chaos" and blatantly conflict with the constitutional authority of federal immigration authorities.

The legislation has been cheered on by conservatives but harshly criticized by civil rights and immigration advocates.

Some local authorities say they do not have enough resources to fully enforce the law and have no plans to make it a priority.

Texas Solicitor General Aaron Lloyd Nielson said before the 5th U.S. Circuit Court of Appeals on Wednesday that Texas has a right to defend itself and the federal government should not get in the way.

PHOTO: Greg Abbott, governor of Texas, during a news conference at Shelby Park along the Rio Grande River in Eagle Pass, Texas, Feb. 8, 2024. (Sergio Flores/Bloomberg via Getty Images)
PHOTO: Greg Abbott, governor of Texas, during a news conference at Shelby Park along the Rio Grande River in Eagle Pass, Texas, Feb. 8, 2024. (Sergio Flores/Bloomberg via Getty Images)

"Texas has decided that we are at the epicenter of this crisis -- we are on the front line -- and we are going to do something about it," Nielson told the court.

He argued that the SB4 effectively "mirrors" federal law by outlawing illegal border crossings on a state level.

Department of Justice Attorney Daniel Tenny argued to the court that the responsibilities of enforcing immigration law are exclusively a federal responsibility and that Texas is interfering with deportation processes.

"There are plenty of things that a state can do that would affect the problems that Texas is complaining about," Tenny said.

The panel appeared divided on the question of whether to put SB4 on hold as litigation proceeds on the merits of the dispute.

PHOTO: Greg Abbott, governor of Texas, during a news conference at Shelby Park along the Rio Grande River in Eagle Pass, Texas, Feb. 8, 2024. (Sergio Flores/Bloomberg via Getty Images)
PHOTO: Greg Abbott, governor of Texas, during a news conference at Shelby Park along the Rio Grande River in Eagle Pass, Texas, Feb. 8, 2024. (Sergio Flores/Bloomberg via Getty Images)

It remains unclear how certain provisions of the law would interact with federal enforcement. For example, the court questioned Nielson about what would happen if a migrant was delivered to a port of entry and then re-released by Border Patrol.

"This is uncharted because we don't have any cases on it," Nielson said. But he said that he believes such migrants could be re-arrested by the state under SB4.

Chief Judge Priscilla Richman, a George W. Bush appointee, several times voiced skepticism of Texas' claims. "This is the first time, it seems to me, that a state has claimed it has the right to remove illegal aliens," she said. "This is not something that has historically been exercised by states, right?"

Judge Andrew Oldham -- a Donald Trump appointee, former general counsel to Gov. Abbott and former deputy solicitor general of Texas -- was the most sympathetic to the state.

PHOTO: U.S. soldiers and law enforcement officers stand over a small group of immigrants who had crossed the Rio Grande into the United States on March 18, 2024 in Eagle Pass, Texas. (John Moore/Getty Images)
PHOTO: U.S. soldiers and law enforcement officers stand over a small group of immigrants who had crossed the Rio Grande into the United States on March 18, 2024 in Eagle Pass, Texas. (John Moore/Getty Images)

The panel's third judge, Joe Biden appointee Irma Ramirez, also the first Latina to serve on the 5th Circuit, did not ask any questions during the argument.

Legal analysts expect the court to render a decision relatively quickly, in days or weeks, on whether to stay SB4 for the duration of litigation.

Whatever they decide will almost certainly end up back at the U.S. Supreme Court which, despite temporarily allowing the law to go into effect on Tuesday, still has not weighed in officially on the merits of the state law.

ABC News' Armando Garcia, James Scholz and Mireya Villarreal contributed to this report.

'Uncharted': Texas argues in support of sweeping immigration law amid scrutiny in court originally appeared on abcnews.go.com