A coalition of civil rights groups filed a new lawsuit Monday seeking to halt parts of a Texas law that would allow police officers in the Lone Star State to arrest migrants suspected of crossing into the U.S. across the U.S.-Mexico border illegally.
Senate Bill 4, known as S.B. 4, is set to take effect on May 15 after a federal appeals court vacated an injunction last week that had prevented its enforcement since 2024. The appeals court found that the plaintiffs who originally challenged the law did not have standing to sue.
S.B. 4 establishes a state-level crime for entering the country illegally and authorizes state magistrates to order certain individuals to leave the country if they are convicted. Courts have long maintained that immigration enforcement has historically been treated as the responsibility of the federal government, but Texas Republicans who passed the measure attempted to challenge that precedent.
What the Left Is Saying
The Texas Civil Rights Project, American Civil Liberties Union and ACLU of Texas argue that S.B. 4 is unconstitutional because immigration law is exclusively a federal matter and federal law should preempt state law. The groups are attempting to block four specific provisions: the creation of a crime for re-entering the country illegally even if a person has obtained legal status such as a green card; granting state magistrates authority to issue deportation orders; the creation of a crime for failing to comply with a magistrate's deportation orders; and a requirement that magistrates continue prosecution even if a person has a pending immigration case under federal law, such as an asylum claim.
Kate Gibson Kumar, an attorney at the Texas Civil Rights Project, said in a statement: "Our fight against S.B. 4 isn't over until justice wins. S.B. 4 is not only unconstitutional, but a vile law that uses our Texas resources to harm communities across our state."
Adriana Piñon, legal director at the ACLU of Texas, said: "S.B. 4 would transform our police and judges into immigration agents — threatening neighbors who have families here, who have lived here for years, even those who have legal status. Immigration enforcement is exclusively the federal government's arena, and no state has ever claimed the power Texas threatens to wield here."
Cody Wofsy, deputy director of the ACLU's Immigrants' Rights Project, argued that S.B. 4 is "cruel and illegal": "Every court to have reached the merits of laws like S.B. 4 has found them to be unconstitutional," he said.
What the Right Is Saying
Texas Republican lawmakers who authored and passed S.B. 4 contend that the state has a right to address border security concerns when the federal government fails to act. The law was passed amid increased migrant crossings at the U.S.-Mexico border, with supporters arguing that Texas communities have been left vulnerable without adequate federal intervention.
The appeals court's recent ruling found that previous challengers lacked standing to sue, effectively clearing the way for enforcement. Texas Attorney General Ken Paxton's office has defended S.B. 4 as a necessary tool for state-level immigration enforcement.
What the Numbers Show
S.B. 4 was originally passed by Texas lawmakers in 2023 and signed into law that year. The measure cleared its initial legal hurdle last week when the 5th U.S. Circuit Court of Appeals vacated an injunction that had blocked enforcement since early 2024, finding plaintiffs lacked standing to bring the challenge.
The law is scheduled to take effect on May 15 unless another court issues an injunction. Monday's filing represents a renewed legal effort by civil rights groups after the previous case was dismissed on procedural grounds.
The Bottom Line
This lawsuit marks the latest chapter in an ongoing legal battle over state-level immigration enforcement powers. The civil rights coalition is pursuing new arguments after the appeals court found that earlier challengers lacked standing to sue, meaning courts have not yet ruled on the merits of whether S.B. 4 is constitutional.
The case raises fundamental questions about the separation of powers between federal and state governments regarding immigration policy. If the lawsuit fails and the law takes effect, Texas would become the first state in modern history to enforce its own immigration laws, a shift that could have far-reaching implications for federal-state authority on border security.