By Ted Hesson

WASHINGTON (Reuters) – A federal judge in Texas on Tuesday temporarily blocked a move by new U.S. President Joe Biden to halt the deportation of many immigrants for a 100-day period, a swift legal setback for his ambitious immigration agenda.

U.S. District Judge Drew Tipton, an appointee of former President Donald Trump in the Southern District of Texas, issued a temporary restraining order that blocks the policy nationwide for 14 days following a legal challenge by Texas.

The Biden administration is expected to appeal the ruling, which halts the deportation freeze while both parties submit briefs on the matter.

Biden promised on the campaign trail to enact a 100-day moratorium on deportations if elected, a proposal that contrasted sharply with the immigration crackdown promoted by Trump, a Republican.

After Biden took office on Wednesday, the top official at the U.S. Department of Homeland Security (DHS) issued a memo that ordered a pause on many deportations to enable the department to better deal with “operational challenges” at the U.S.-Mexico border during the pandemic.

In a complaint filed on Friday, Texas Attorney General Ken Paxton said the state would face irreparable harm if the deportation freeze was allowed to go into effect. Paxton, a Republican, said it would increase education and healthcare costs as more immigrants remained in Texas illegally.

Paxton also said it went against the terms of an enforcement agreement Texas brokered with the Trump administration less than two weeks before Biden took office.

Tipton said in the order on Tuesday that Texas had “a substantial likelihood of success” on at least two of its claims, including that the deportation freeze violated a federal immigration law stating that authorities “shall remove” immigrants with final deportation orders within 90 days.

The judge also found it likely that Texas would succeed on its claim that the Biden administration “arbitrarily and capriciously departed from its previous policy without sufficient explanation” when it issued the moratorium.

Paxton praised the ruling in a statement, saying a deportation moratorium would “endanger Texans and undermine federal law.”

Approximately 1.2 million immigrants in the United States have final orders of removal, a spokeswoman for U.S. Immigration and Customs Enforcement (ICE) told Reuters.

As of Jan. 16, ICE was holding around 6,000 detainees with final deportation orders, the spokeswoman said.

The number of detained migrants has dropped sharply during the pandemic, falling by roughly two-thirds.

Kate Huddleston, an attorney with the American Civil Liberties Union of Texas, which filed a brief in support of the Biden administration, criticized the Texas lawsuit in a statement after the ruling.

“The administration’s pause on deportations is not only lawful but necessary to ensure that families are not separated and people are not returned to danger needlessly while the new administration reviews past actions,” she said.

(Reporting by Ted Hesson in Washington; Additional reporting by Mica Rosenberg in New York and Kristina Cooke in Los Angeles; Editing by Ross Colvin, Franklin Paul, Mark Heinrich and Marguerita Choy)