Republicans in Arizona voted this afternoon to put a measure on the state’s ballots in November that would make illegal immigration a state crime. If passed, the measure would give local authorities the power to arrest, jail and deport unauthorized migrants.

The proposal is similar to laws recently passed by Republicans in Texas and Iowa that challenged the federal government’s exclusive authority to enforce immigration laws. Like those, it is likely to face court challenges if passed. But Republicans are hoping the measure can convince anti-immigration conservatives and unenthusiastic independents to vote in a swing state that could be crucial in the presidential race.

President Biden is also hardening his border policies in an effort to ease pressure on the immigration system and address voters’ rightward shift on immigration. Today, he issued an executive order that prevents migrants from seeking asylum at the U.S.-Mexico border until illegal crossings drop significantly; it could go into effect tomorrow. Here’s how it works.

Biden’s move to restrict long-established asylum protections for migrants echoes Donald Trump’s attempted crackdown in 2018, which many Democrats, including Biden himself, criticized. The American Civil Liberties Union said it planned to challenge the executive action in court.

“The administration has left us little choice but to sue,” said Lee Gelernt, a lawyer at the A.C.L.U. “It was unlawful under Trump and is no less illegal now.”

In related news, San Diego has become a migrant hot spot. My colleague Jonathan Wolfe explained what it’s like there.