But with the immigration restrictions going away on Wednesday it's unclear if the Supreme Court will intervene. The nineteen states Monday asked the court for an emergency stay that would keep Title 42 in place.

“This Court's review is warranted given the enormous national importance of this case. It is not reasonably contestable that the failure to grant a stay will cause an unprecedented calamity at the southern border,” the states wrote in their request.

The immigration restrictions, often referred to as Title 42, were put in place under then-President Donald Trump in March 2020 and have prevented hundreds of thousands of migrants from seeking asylum in the U.S. in recent years. But as they're set to expire thousands more migrants are packed in shelters on Mexico's border with the U.S.

Immigration advocates sued to stop the use of Title 42 to limit who can apply for asylum, saying that the policy goes against American and international obligations to people fleeing to the U.S. to escape persecution. And they've argued that things like vaccines and treatments for the coronavirus have made the policy outdated.

Conservative-leaning states have argued that lifting of Title 42 will lead to a surge of migrants into their states and take a toll on government services like health care or law enforcement. They also charge that the federal government has no plan to deal with an increase in migrants. With a Republican-controlled House set to take charge in early January, the imminent lifting of the pandemic-era restrictions has become a hot-button political issue.?

The D.C. Circuit Court of Appeals rejected efforts by 19 conservative-leaning states late Friday to intervene in the case, saying they'd waited too long, leading the states to appeal to the Supreme Court.?