PHOENIX (AP) — Arizona voters have approved letting local police arrest migrants suspected of illegally entering the state from Mexico, an authority that would encroach on the federal government's power over immigration enforcement but would not take effect immediately, if ever.

With the approval of Proposition 314, Arizona becomes the latest state to test the limits of what local authorities can do to curb illegal immigration. Within the past year, GOP lawmakers in Texas, Iowa and Oklahoma have passed immigration laws. In each case, federal courts have halted the states' efforts to enforce them.

The only presidential battleground state that borders Mexico, Arizona is no stranger to a bitter divide on the politics of immigration. Since the early 2000s, frustration over federal enforcement of Arizona's border with Mexico has inspired a movement to draw local police departments, which had traditionally left border duties to the federal government, into immigration enforcement.

The state Legislature approved an immigrant smuggling ban in 2005 that let then-Maricopa County Sheriff Joe Arpaio conduct immigration crackdowns, a 2007 prohibition on employers knowingly hiring people in the country illegally, and a landmark 2010 immigration law that required police, while enforcing other laws, to question the legal status of people suspected of being in the country without authorization.

Arizona voters have been asked to decide matters related to immigration before. They approved a 2004 law denying some government benefits to people in the country illegally and a 2006 law declaring English to be Arizona's official language. They also rejected a 2008 proposal that would have made business-friendly revisions to the state law barring employers from hiring people who are in the country without authorization.

Arizona GOP lawmakers say the proposal was necessary to help secure the border, as they blamed the Biden administration for an unprecedented surge of illegal immigration. Record levels of illegal crossings have plummeted in recent months, following moves by the White House to tighten asylum restrictions.

Opponents of Proposition 314 argue it would harm Arizona's economy and reputation, as well as lead to the racial profiling of Latinos. They cite the profiling Latinos endured when Arpaio led the Maricopa County Sheriff's Office. In 2013, a federal judge ruled Latinos had been racially profiled in Arpaio's traffic patrols that targeted immigrants, leading to a court-ordered overhaul of the agency that's expected to cost taxpayers $314 million in legal and compliance costs by mid-summer 2025.

Kelli Hykes, who works in health policy and volunteers for Greg Whitten, the Democratic nominee in the race for Arizona's 8th Congressional District, said she thought carefully about how to vote on the immigration measure but declined to share her choice.

"It's so polarizing, and there are folks in my family that are going to be voting one way and I'm voting another," Hykes said.

Proposition 314 makes it a state crime for people to illegally enter Arizona from Mexico outside official ports of entry, permitting local and state law enforcement officers to arrest them and state judges to order their deportations. Those who enforce the law would be shielded from civil lawsuits.

These provisions, however, wouldn't be enforceable immediately. A violator couldn't be prosecuted until a similar law in Texas or another state has been in effect for 60 consecutive days.

The Arizona GOP lawmakers who voted to put the measure on the ballot were referring to Texas Senate Bill 4. The bill, signed into law by Texas Gov. Greg Abbott in December, was supposed to allow local and state law enforcement to arrest people accused of entering Texas illegally from Mexico.

A federal appeals court put it on hold in March. The following month, a panel of federal judges heard from a Texas attorney defending the law and Justice Department attorneys arguing it encroached on the federal government's authority over enforcing immigration law. The panel has yet to release its decision.

Other provisions of Proposition 314 aren't contingent upon similar laws outside Arizona. The approval of the measure immediately makes selling fentanyl that results in a person's death a felony punishable by up to 10 years in prison, and a crime for noncitizens to submit false documentation when applying for employment or attempting to receive benefits from local, state and federal progra