On Tuesday, the Supreme Court will hear oral arguments in a case that could have significant effects on both the executive branch’s authority to issue regulations governing the application of U.S. immigration laws and the capacity of states and organizations to contest those regulations.

The directive given by Homeland Security Secretary Alejandro Mayorkas in September 2021 to Immigration and Customs Enforcement (ICE) agents to prioritize the arrest of migrants who have recently entered the country illegally as well as immigrants who are thought to pose a threat to national security or public safety is at the center of the court case, known as U.S. v. Texas, and effectively exempts other unauthorized immigrants without serious criminal records from enforcing immigration laws.

The Biden administration claimed that the directive allowed ICE to focus its limited resources, including 6,000 deportation agents, on efforts to apprehend and deport individuals who were believed to pose a threat to public safety. The government, according to the administration, lacks the personnel and resources necessary to apprehend and deport the millions of immigrants who are thought to be residing illegally in the United States.

Republican representatives from Texas and Louisiana sued Mayorkas for his memo, claiming it prevented ICE agents from fully enforcing immigration laws in the country. A federal judge in Texas sided with the state authorities in June and ruled that the Biden administration regulations were unconstitutional. He also barred ICE agents from enforcing the rules.

After that, the Biden administration petitioned the Supreme Court to get involved. The high court agreed to hear the case on the merits but declined to lift the ban on Mayorkas’ memo in July.

The Supreme Court will have to decide whether Texas and Louisiana had the right to sue the Biden administration, whether Mayorkas’ memo is legal, and whether federal courts have the authority to overturn immigration enforcement policies after hearing the oral arguments on Tuesday.

Customs and Border Protection (CBP) is in charge of stopping unauthorized immigrants and illegal drugs at U.S. borders, while ICE is in charge of apprehending, holding, and deporting immigrants who have broken immigration laws inside the country.

The Obama administration issued several memos instructing ICE agents to concentrate on arresting certain classes of deportable immigrants, such as recent border crossers and those deemed to pose a threat to public safety or national security, in response to progressive criticism of mass deportations. Additionally, it stopped the widespread ICE detainments at workplaces that caused outrage among advocates under the George W. Bush administration.

The number of unauthorized immigrants that ICE agents can detain increased significantly after the Trump administration overturned the Obama memos. Soon after assuming office, President Biden’s administration reversed the Trump directives and issued a memo telling ICE once more to concentrate on deporting people who pose threats to border security, public safety, or national security.

Mayorkas included the same three priority groups for arrest in his September 2021 memo, but he did away with a categorical definition for the public safety category. Instead, he instructed officers to consider both “mitigating factors” and “aggravating factors” when determining whether to make an arrest. “Mitigating factors” include an immigrant’s age, length of time in the country, and military service.

The Mayorkas directive is a component of the Biden administration’s plan to reform ICE. The administration has further directed the agency to stop detaining families with young children for extended periods of time and making large-scale arrests at work sites. Additionally, pregnant women, people who have recently been the victims of serious crimes, and veterans of the military should not be detained.

The Biden administration policies have resulted in a significant drop in ICE arrests and deportations in the interior of the United States, along with operational limitations brought on by the COVID-19 pandemic. In fiscal year 2021, ICE carried out 59,011 deportations, the fewest ever. According to government statistics, ICE deportations increased to 69,019 during the fiscal year 2022, which came to an end on September 30.

In light of record numbers of migrants being apprehended at the U.S.-Mexico border, Republican lawmakers have sharply criticized the historically low number of deportations and charged that the Biden administration has not fully enforced immigration laws.

U.S. border officials have used a public health law known as Title 42 during the pandemic to quickly turn away a sizable portion of the migrants they encounter.  Because Title 42 is a public health authority, expulsions under the policy are not counted as formal deportations.