U.S. President Joe Biden speaks with U.S. Customs and Border Protection officers as he visits the U.S.-Mexico border in El Paso, Texas, on Jan. 8, 2023.

A federal judge on Thursday ruled against a Biden administration initiative designed to make it easier for certain undocumented immigrants married to U.S. citizens to obtain citizenship.

The program, hailed as one of the most significant presidential actions aimed at assisting immigrant families in recent years, allowed undocumented spouses and stepchildren of U.S. citizens to apply for a green card without first leaving the country.

The temporary reprieve from deportation provided a brief sense of security to an estimated 500,000 immigrants who were expected to benefit from the program before U.S. District Judge J. Campbell Barker, based in Texas, halted it in August, just days after applicants submitted their paperwork.

Barker ruled on Thursday that the Biden administration had exceeded its authority by implementing the program and had stretched the legal interpretation of relevant immigration law “past its breaking point.”

The short-lived Biden administration initiative, known as “Keeping Families Together,” was unlikely to have remained in place after Donald Trump assumes office in January. However, its early termination creates greater uncertainty for immigrant families as many anticipate Trump’s return to the White House.

Trump’s this week sets the stage for a swift crackdown on undocumented individuals after the Republican ran on promises of “mass deportation.” The president-elect galvanized his supporters on the campaign trail with a series of anti-immigrant statements, including that immigrants were “poisoning the blood” of the nation.

During his first term, Trump appointed Barker as a judge in Tyler, Texas, a city located within the 5th U.S. Circuit Court of Appeals, a preferred venue for advocates promoting conservative arguments.

Barker had suspended the immigration initiative after Texas and 15 other states, led by their Republican attorneys general, filed a legal challenge accusing the executive branch of circumventing Congress to assist immigrant families for “blatant political purposes.”

Republicans argued that the initiative would result in increased costs for their states and could attract more migrants to the U.S.

The policy would have applied to individuals who have resided continuously in the U.S. for at least 10 years, do not pose a security threat and have utilized the existing legal authority known as “parole in place” that offers deportation protections.

Those married to a citizen by June 17, the day before the program was announced, could pay a $580 application fee and submit a comprehensive application explaining why they deserve humanitarian parole. If approved, applicants would have a three-year period to pursue permanent residency and obtain work authorization.

It remained unclear on Thursday whether any individuals had been granted approval under the program, which only accepted applications for approximately a week before the federal judge placed it on hold.

Noncitizen spouses are already eligible for legal status but often must apply from their home countries. The process typically involves a multi-year waiting period outside of the U.S., which can lead to separation of family members with different immigration statuses.