While Title 42 was in force, migrants did not face penalties for trying to cross the border illegally multiple times. They often do so to try to increase their chances of staying in the United States, even if only temporarily.

Now that the rule is no longer in effect, migrants will once again face repercussions — a fine and jail time — if they are caught crossing the border illegally a second time.

Migrants from Mexico, Guatemala, Honduras and El Salvador accounted for 60 percent of the expulsions under Title 42. With its lifting, migrants from those countries have regained access to asylum under U.S. immigration law. Asylum access for migrants from those countries in particular, however, has always been narrow.

For Central Americans, that narrow window closes even more. The Biden administration has enforced new policies that require migrants to apply for humanitarian benefits available to them before they are allowed into the United States. Or they must show that they have tried to apply for asylum in countries they traveled through — like Mexico — before crossing into the United States illegally and being considered for asylum.

The administration does plan to conduct swift interviews with migrants while they are in custody at the border to establish whether they have a “credible fear” of returning to the country they fled. A previous, similar program was used for a time during the Trump administration. A majority of migrants who were interviewed under this policy were found not to have a credible fear, according to an analysis by the Government Accountability Office.

“No matter what nationality you are, if you did not apply for asylum in Mexico, or in another country and are rejected, your access to asylum is going to be significantly smaller or narrower than it was before,” said Ariel Ruiz Soto, a policy analyst at the Migration Policy Institute, a nonpartisan research group in Washington, D.C.

May 12, 2023, 2:29 p.m.

Edgar Sandoval Reporting from McAllen, Texas for The New York Times

At a shelter for migrants in McAllen, Texas, operated by Catholic Charities, volunteers said they were working around the clock to keep up with the flow, but they have managed so far. Yesterday the shelter reached its capacity of 1,500 people, and volunteers had to turn away about 200 migrants, who were taken to tents set up at a nearby park. “I have never seen it this full,” Juan Mercado, a worker at the shelter, said. “But we are able to help everyone or we send them to the park.”