The Supreme Court’s ruling late Tuesday, which ordered the Biden administration to reinstate the Trump-era Remain-in-Mexico policy, marks the latest legal defeat for the administration on the subject of immigration.

In a 6-3 decision, the court denied a request to stop a federal court ruling ordering the administration to reinstate the Migrant Protection Protocols – which has become known as "Remain-in-Mexico" – a major 2019 border security program that kept migrants in Mexico as they awaited their hearings.

MISSOURI AG DECLARES DECISION A ‘HUGE VICTORY FOR BORDER SECURITY’

Biden began dismantling MPP shortly after entering office, and formally ended it in June, one of a number of moves the administration made to reverse President Donald Trump’s border policies. Texas and Missouri sued, arguing that the ending of the policy in June was both harmful to their states and in breach of the Administrative Procedures Act (APA).

Critics called the policy, which led to the establishment of tent courts across the border, cruel and dangerous for migrants. The Trump administration said the policy ended catch-and-release, reducing the pull factors bringing migrants north. President Biden campaigned on ending the policy.

In the initial ruling, Judge Matthew Kacsmaryk ordered the Biden administration "to enforce and implement MPP in good faith" until it has been "lawfully rescinded" in compliance with the APA, and until the federal government has enough detention capacity to detain all migrants subject to mandatory detention. 

The Biden administration said Tuesday it would appeal the ruling, but also comply with the order.

"Alongside interagency partners, DHS has begun to engage with the Government of Mexico in diplomatic discussions surrounding the Migrant Protection Protocols (MPP)," the statement from the Department of Homeland Security said.

TEXAS AG PAXTON VOWS TO HOLD BIDEN ADMINISTRATION ACCOUNTABLE AFTER WIN

The attorneys general of Missouri and Texas declared the Supreme Court victory an important win over the Biden administration, tying it to the crisis at the border.

"What we’ve seen of course since Biden's reversal of MPP...has been an unmitigated disaster at the southern border," Schmitt told Fox News in an interview Wednesday. "It’s been a humanitarian crisis, it’s been a national security crisis, and so to get this victory and reinstate President Trump’s successful policy is a big win."

"It’s fundamentally important because we have a president who looked at federal law and said, ‘I don’t have to follow federal law, I’m the president, I do what I want, I don't care if it’s in statute, I don't care if Congress passed it, I can do what I want, I’m the president,’" Paxton told Fox News. "So it’s even bigger than immigration, it’s about the Constitution, the fact that even the president is supposed to follow the law."

It marks the latest legal defeat to the Biden administration’s efforts to change the policies of the Trump administration.

FEDERAL JUDGE BLOCKS BIDEN ADMIN'S ICE RULES THAT NARROWED ILLEGAL IMMIGRANT ARREST PRIORITIES

Last week, a federal judge imposed a preliminary injunction on the Biden administration’s rules for Immigration and Customs Enforcement (ICE) officers that significantly narrowed the categories of illegal immigrants being targeted for arrest and deportation.

The guidance, issued in February, limited agents to focusing on three categories of immigrants: those who pose a threat to national security; those who have crossed the border since Nov. 1, and those who committed "aggravated felonies." It followed up on Jan. 20 guidance issued by the Department of Homeland Security.

But Judge Drew Tipton ruled that the policy was in violation of congressional mandates, and that Louisiana and Texas, which filed the lawsuit, were likely to succeed in their claim that the policy violated the Administrative Procedures Act (APA.)

The Republican AGs had argued that narrowing arrests would hurt their states financially – including with increased detention, education, and health care costs – and also damage their interests in protecting their citizens from criminal illegal immigrants.

Tipton ruled that the link between the guidance and the harm suffered by the states is "virtually unassailable" and that "the undisputed evidence demonstrates that the memoranda are already causing a dramatic increase in the volume of criminal aliens released into the public."

CLICK HERE TO GET THE FOX NEWS APP

Judge Tipton is the same judge who barred the Biden administration from imposing a 100-day moratorium on ICE deportations at the beginning of the administration after a lawsuit from Texas.

The Biden administration ultimately dropped its effort to impose the moratorium.

"The 100-day period during which DHS would have paused the execution of certain final removal orders has now otherwise expired and would no longer be in effect under the terms of the memorandum," a DHS statement said in May.