The measure, called “Title 42,” is “arbitrary” and does not follow federal rules, Judge Emmet Sullivan said.

This procedure does not allow legal recourse, even for those who wish to file an asylum application – with rare exceptions, such as for Ukrainians since the beginning of the Russian invasion.

The court ruling leaves Democratic President Joe Biden’s administration with few options to prevent the entry of the many migrants seeking to cross the border into Mexico.

But immigration is an explosive political subject. The Republican opposition relentlessly attacks Joe Biden, accused of having turned the border into a sieve.

Without condemning the judge’s decision, the American authorities asked for a reprieve of several weeks, to allow them to prepare for its application.

“Title 42” was implemented by the Trump administration in March 2020, at the start of the Covid-19 pandemic, and has been the subject of several separate legal battles.

Tuesday’s decision was made in a lawsuit brought by the powerful civil rights group ACLU. She accused the government of carrying out “summary evictions”.

The Biden administration, which initially continued to use this controversial device, then sought to lift it.

The Republican governors of some twenty states had then taken legal action to prevent it.

In May, a judge, this time in Louisiana, had ruled that the measure should continue to be applied.

The plaintiff States asserted in particular that the lifting of this measure would cause an upsurge in border crossings and consequently an increase in the number of migrants residing illegally on their soil.

“Title 42” is a public health measure that was adopted in 1893 to protect the United States against the numerous epidemics of cholera and yellow fever that were occurring at the time. It was only very rarely implemented, until 2020.

Since then, this device has been used nearly two million times.

More than 200,000 people have been stranded at the border every month this year – many, if not the majority, of them because of “Title 42”.

Human rights activists assure that this measure results, paradoxically, in an upsurge in attempts to enter American soil.

Because there are no legal or judicial consequences for migrants expelled under this system, who can try their luck as many times as they wish.

“We have always maintained that using Title 42 against asylum seekers is inhumane and motivated by purely political considerations,” said attorney Lee Gelernt, who argued against the proceeding on behalf of the ACLU.

“Let’s hope this decision puts an end to this terrible practice once and for all.”