Texas Attorney General Ken Paxton sued the Biden administration Friday to block the president’s 100-day “pause” on most deportations, alleging the move violates an agreement signed between the state and the Department of Homeland Security during the final days of President Donald Trump’s term.

Biden this week ordered a freeze on most deportations from the interior of the United States, saying his administration wants to reassess the operations of U.S. Immigration and Customs Enforcement (ICE) and more narrowly focus the agency on immigrants who pose public safety and national security threats.

Paxton’s lawsuit claims the deportation freeze defies an agreement between Texas and DHS finalized Jan. 8 — less than two weeks before Trump left office — requiring the department to provide 180 days notice before making changes to immigration policy and enforcement practices.

Several legal scholars have described the DHS agreements with Texas and other states as highly unusual and an attempt to stop Biden from undoing Trump’s immigration policies by effectively giving states veto power.

During a hearing Friday in U.S. District Court for the Southern District of Texas, Judge Drew Tipton, a Trump appointee, did not issue a ruling on the state’s motion for a preliminary injunction.

Whether the agreements can block Biden’s moves is unclear. Paxton’s suit claimed they are “binding and enforceable.”

“On its first day in office, the Biden Administration cast aside congressionally enacted immigration laws and suspended the removal of illegal aliens whose removal is compelled by those very laws,” said the complaint, filed in U.S. District Court for the Southern District of Texas.

“In doing so, it ignored basic constitutional principles and violated its written pledge to work cooperatively with the State of Texas to address shared immigration enforcement concerns,” it adds. “This unlawful reversal will cause Texas immediate and irreparable harm if it is not enjoined.”

The White House and DHS did not respond to requests for comment.

Paxton, a Trump ally who was an adviser to the failed quest to overturn the 2020 election, is facing legal troubles of his own and is under investigation for alleged state securities fraud.

Sarah Pierce, a policy analyst at the Migration Policy Institute, a nonpartisan D.C. think tank, said the agreements DHS signed with Texas, other states — and in some cases local sheriff’s offices — appeared to be “unprecedented.”

“These agreements are unenforceable as written,” she said. “Under the way our government is structured, it’s not possible for states and localities to force the federal government to act on something that is within its responsibilities under the Constitution.”

Added Pierce: “It’s a pretty extraordinary act to reach into a new administration and oblige them to continue immigration enforcement at the level it was at during the Trump administration.”

Another question is whether the DHS official who signed the agreement, Ken Cuccinelli, had the legal authority to do so. Cuccinelli, the “Senior Official Performing the Duties of the Deputy Secretary,” was part of an interim leadership structure at DHS that operated under an invalid order of succession, according to court rulings, and in violation of the Federal Vacancies Reform Act.

Biden’s deportation pause has thrilled immigrant advocates and longtime critics of ICE, which under Trump cast a wider net and gave agents more latitude to arrest immigrants who had not committed serious crimes.

The pause does not shield anyone who arrived after Nov. 1, so deportations of recent border crossers will continue. ICE can also return individuals who are considered national security threats as well as violent felons, though the memo instructs agents to prioritize those who are to be released from prison to now. The new priorities take effect Feb. 1. But the 100-day freeze has outraged Republicans and others who argue the reprieve should not apply to violent and serious felons at all.

“If you’re a dangerous person and you’re here illegally and you go to prison and you serve that time you should be sent home,” said Emilio T. González, who headed U.S. Citizenship and Immigration Services under President George W. Bush. “You don’t want that person living next to you, do you?”

But others said the 100-day pause allows Biden to take stock of immigration agencies that were given wide latitude under the Trump administration, and create new priorities for enforcers to follow.

Leon Fresco, a former Justice Department lawyer under the Obama administration, called the 100-day freeze and new priorities a “bold” move and that he expected a “massive backlash” from Republicans. “Is it something that you would do to be politically safe? No,” Fresco said.

But he said it is smart to pause, assess the system and create new policies, while preventing deportations that do not match the new administration’s priorities. And he said now is the time to do it, because detention numbers are their lowest in years, the coronavirus is infecting detainees and jailers alike and immigration courts are swamped with cases. DHS could adjust the priorities later when deportations resume, he said.

“Everybody knows what they want to do in the Biden administration,” he said. “You don't want to deport grandma, but you do want to deport a violent person who committed rape or armed robbery or something like that.”

Lawyers noted that the new DHS enforcement priorities are a guideline, and that immigration agents can still detain someone who has a violent record regardless of when they were released from jail.