The migrant border policy Title 42 will remain in effect for months while legal challenges play out, the Supreme Court ruled 5-4 on Tuesday.

The Supreme Court has taken up the case to consider whether 19 states could challenge the policy's end as desired by the Biden administration.

The court on a 5-4 vote granted a request by a group of Republican state attorneys general to put on hold a judge's decision invalidating the emergency order known as Title 42 while it considered whether they could intervene to challenge the ruling.

The states had argued lifting the policy could lead to an increase in already-record border crossings.

Supreme Court Chief Justice John Roberts, a member of the court's 6-3 conservative majority, issued a temporary administrative stay Dec. 19 maintaining Title 42 while the court considered whether to keep the policy in place for longer. The policy had prior to his order been set to expire Dec. 21.

Conservative Justice Neil Gorsuch joined with the court's three liberal members – Justices Sonia Sotomayor, Elena Kagan Ketanji Brown Jackson – in dissenting from Monday's order leaving Title 42 in effect.

The Title 42 immigration policy, first put in place by former President Donald Trump at the start of the COVID-19 pandemic, ensures federal officials can continue to immediately expel migrants at U.S. borders.

The Supreme Court was weighing whether to keep the powers in place following months of legal battles brought on by Republican-led states after President Joe Biden's administration moved to end the Trump-era policy, which was set to lapse this week until the court agreed to take it up.

The administration has yet to lay out any systemic changes to manage an expected surge of migrants if the restrictions end. And a bipartisan immigration bill in Congress has been buried just as Republicans are set to take control of the House.

The Biden administration has been reluctant to take hardline measures that would resemble those of his predecessor. That has resulted in a surge of migration through the southern border.

"The Democrats have lost the messaging war on this," said Charles Foster, a longtime immigration attorney in Texas who served as an immigration policy adviser to Republican George W. Bush but now considers himself independent. "The tragedy is, Democrats more than anyone should focus on this issue, because unless and until it can be fixed, and the perception changes, we'll get nothing ever through Congress."

Anyone who comes to the U.S. has the right to ask for asylum, but laws are narrow on who actually gets it. Under Biden, migrants arriving at the border are often let into the country and allowed to work while their cases progress. That process takes years because of a 2-million-case backlog in the immigration court system that was exacerbated by Trump-era rules.

Title 42 allows border officials to deny people the right to seek asylum, and they have done so 2.5 million times since March 2020. The emergency health authority has been applied disproportionately to those from countries that Mexico agreed to take back: Guatemala, Honduras, El Salvador and more recently Venezuela, in addition to Mexico.

Biden has been working to expand legal immigration and has undone some of the most restrictive Trump policies. But the administration kept the policy in place until this spring, and even expanded its use after announcing it would end.

Republican say there will be will be chaos if it is lifted. But even with Title 42 in place, border officials have been encountering more migrants than ever before. In the budget year that ended Sept. 30, migrants were stopped 2.38 million times, up 37% from 1.73 million times the year before.

"I don't know why it's taking them so long to get serious about deterrence," Sen. Shelley Moore Capito, R-W.Va., said of the Biden administration. Capito is an incoming member of the Senate Republican leadership and the top GOP senator on the committee that oversees money for Homeland Security, the federal agency that manages border security.

Border officials have braced for an expected increase, and migrants who have arrived are unsure of how asylum processes will work when the policy ends. Homeland Security officials have reported faster processing for migrants in custody on the border, more temporary detention tents, staffing increases and more criminal prosecutions of smugglers.

They say progress has been made on a plan announced in April but large-scale changes are needed. Meanwhile, the Senate's Republican leadership killed a bipartisan immigration bill that would have addressed some of these issues.

The split is not just inside Congress. One in 3 U.S. adults believes an effort is underway to replace native-born Americans with immigrants for electoral gains, according to an AP-NORC survey.

Biden and his aides have said they are working to divert migrants coming out of Central America and helping provide aid to poorer nations that are bleeding people headed for the U.S. But the president is limited without action from Congress.

White House press secretary Karine Jean-Pierre said the administration is surging assistance to the border and will continue to do so. But "the removal of Title 42 does not mean the border is open," she said. "Anyone who suggests otherwise is simply doing the work of these smugglers who again are spreading misinformation, which is very dangerous."

A year-long appropriations bill passed the Senate on Thursday that would give the Border Patrol 17% more money, as well as 13% more for the Justice Department to develop an electronic case management system for immigration courts.

But Citizenship and Immigration Services, central in the asylum process, only got one third of what Biden had proposed to speed up the system.

Democrats, for their part, say they want policies that reflect America's reputation as a haven for those fleeing persecution. But they can't agree on what that looks like.

Sen. Dick Durbin, D-Ill., has been working on the issue for 20 years. This week, he stood on the Senate floor, sounding dejected as he talked about how Congress could not push through reform.

"It is a humanitarian and security nightmare that is only getting worse," he said. "We're being flooded at the border by people who want to be in the United States, safely in the United States."