Migrant advocates are reeling following the U.S. Supreme Court’s ruling to allow enforcement of the controversial Texas Senate Bill 4, which would give state police and judges the ability to arrest and deport people suspected of unlawfully crossing into the country from the Mexican border. The law was put on hold again hours later by an appeals court.

The bill, signed into law late last year by Texas Gov. Greg Abbott, was initially blocked by a district court. The Fifth Circuit Court of Appeals effectively undid the decision, and the Supreme Court declined to review that suspension, according to the American Civil Liberties Union of Texas. The legislation would have originally gone into effect on March 5.

Supreme Court Justices, in a 6-3 vote on Tuesday, cleared SB 4 to take effect until the appeals court reinstated the district court’s injunction, temporarily blocking the law again as litigation continues to strike it down completely.

“SB4 is cruel, inhumane and clearly unconstitutional,” Kate Melloy Goettel, the senior legal director at the American Immigration Council, said in a statement released after the Supreme Court ruling. “We have a blueprint for fixing our broken immigration system and politically-motivated and hateful laws like SB 4 don’t solve any of our root problems, it only creates more chaos.”

The appeals court scheduled a hearing Wednesday morning to discuss whether the law should be implemented, and according to reports, the judges did not appear receptive to Texas’ arguments that SB 4 “mirrored” federal law.

Opponents and supporters of the immigration law released a flurry of statements following the initial ruling on Tuesday. Texas Attorney General Ken Paxton in a post on X, formerly Twitter, called it a “huge win.” Texas Democratic Party Chair Gilberto Hinojosa said in a statement that the “inhumane” border law would “force American citizens to carry passports in their own neighborhoods.”

Mexico’s Ministry of Foreign Affairs released a statement condemning the law’s implementation, which they said “seeks to stop the flow of migrants by criminalizing them and encouraging the separation of families, discrimination and racial profiling.”

The Mexican government also called into question the safety of the more than 10 million people of Mexican origin who live in Texas and said it would file an amicus curiae brief with the Fifth Circuit court of appeals to provide information about how this law will impact Mexicans and Mexican-Americans and the U.S.-Mexico relations. It has filed briefs of this kind as a third-party opposing anti-immigrant laws in previous litigation in Arizona and Alabama.

“Mexico recognizes the importance of a uniform migration policy and the bilateral efforts with the United States to ensure that migration is safe, orderly and respectful of human rights, and is not affected by state or local legislative decisions,” according to the statement. “In this regard, Mexico will not accept, under any circumstances, repatriations by the State of Texas.”

SB 4, referred to by migrant advocates as one of the most “extreme” anti-immigration laws, would create new state crimes — ranging from misdemeanor to felony — in an attempt to regulate immigration. These charges include: illegal entry from a foreign nation, illegal reentry by certain noncitizens and refusal to comply with an order to leave the country. Local law enforcement could arrest anyone suspected of unlawfully entering the U.S. and state judges would be allowed to issue deportation orders.

The American Civil Liberties Union of Texas, the Texas Civil Rights Project and other civil rights organizations filed a lawsuit late December, which was consolidated into a suit with the Department of Justice, stating the law was unconstitutional and contradicted federal immigration policy.

“Like other state immigration ‘Show Me Your Papers’ laws, SB 4 grants sweeping powers to Texas state and local law enforcement to racially profile and harass Latinos and other communities of color,” UnidosUS President and CEO Janet Murguía said in a statement.