Warren Petersen Steps Into Court to Defend Arizona's Voter-Approved Border Security Law

Arizona Senate President Warren Petersen (R-AZ) is heading to federal court to defend a voter-approved border security measure after an advocacy group filed suit to block one of its key provisions, and he's doing it in part because he doesn't trust the state's attorney general to fully do the job.

Petersen and House Speaker Steve Montenegro (R-AZ) announced Monday they are intervening in federal court to defend Proposition 314, known as the Secure the Border Act, which Arizona voters approved by more than 62 percent in 2024.

The lawsuit, filed by what Petersen describes as an open-borders advocacy group, targets a specific provision that allows state and local law enforcement to arrest individuals who unlawfully enter Arizona between official ports of entry under specified circumstances.

The law also strengthens penalties for fentanyl traffickers whose crimes result in death and requires state agencies to verify eligibility for certain public benefits using the federal SAVE system.

Recent Opposition

Attorney General Kris Mayes (D-AZ) is participating in the case, but Petersen argues her defense has been limited to procedural issues rather than a full-throated defense of the law's policies.

The press release explained that Mayes publicly opposed Proposition 314 before voters approved it and has previously stated that her participation in the lawsuit should not be interpreted as an endorsement of the law. Arizona law and Proposition 314 itself expressly allow legislative leaders to intervene to defend the measure's constitutionality.

"We are intervening because we cannot count on Kris Mayes to fully defend this law," Petersen said. "She opposed it from the beginning and has dismissed it as an unfunded mandate."

Petersen framed the intervention in broader terms, arguing that even with the Trump administration having restored order at the border, there is no guarantee a future administration won't reverse course.

"Proposition 314 is a critical hedge against that possibility, ensuring Arizona has lawful tools to protect its citizens if Washington fails again," he said.

A hearing on the plaintiffs' request for a temporary restraining order is scheduled for July 24, where the court will consider whether to pause the law's enforcement while the legal challenge plays out.