In 2010, Arizona cracked down on illegal immigrants. “We in Arizona have been more than patient waiting for Washington to act,” Gov. Jan Brewer (R) said. “But decades of inaction and misguided policy have created a dangerous and unacceptable situation.”

Last year, the Supreme Court struck down most of Arizona’s immigration legislation, siding with the Obama administration and immigrant rights activists who argued that Arizona’s law intruded on the federal government’s well-established authority over immigration.

“Arizona may have understandable frustrations with the problems caused by illegal immigration,” Justice Anthony M. Kennedy wrote, “but the State may not pursue policies that undermine federal law.”

So what are we to make of the California laws, signed by Gov. Jerry Brown (D) on Oct. 5, that seek to protect the state’s estimated 2.6 million undocumented residents?

Brown sounds as frustrated with Congress as Brewer did: “While Washington waffles on immigration, California’s forging ahead,” he said this month. “I’m not waiting.”

But if it’s unconstitutional for Arizona to enact its own restrictive policy, in tension with federal law, is it constitutional for California to let undocumented immigrants practice law in the state or to penalize employers that report — or “threaten” to report — undocumented employees in retaliation for asserting their rights?

Note that federal law — though spottily enforced — imposes penalties on employers that knowingly hire undocumented workers.

California’s new law limits cooperation with the federal Secure Communities program, under which the fingerprints of arrestees that local police routinely send to the FBI also get routed to U.S. Immigration and Customs Enforcement (ICE).

When ICE registers a “hit” against its database, it tells the state or local jail to hold the individual for up to 48 hours so that federal officials can pursue deportation if appropriate. Between March 2008 and September 2011, Secure Communities led to more than 142,000 deportations.

The Obama administration points to statistics showing that the majority of these were serious criminals or national security threats. But immigrant rights groups argue that the program also swept up many people guilty of only petty misdemeanors or immigration violations.

California’s new law forbids police to detain anyone under Secure Communities unless the individual has been convicted of or formally charged with certain serious crimes such as murder or bribery — but not, say, misdemeanor drunk driving.

It’s the mirror image of a provision of Arizona’s immigration law that essentially required Arizona police officers to check with ICE about everyone they arrested. The Obama administration opposed that as unwanted and unnecessary meddling in federal decision making — but it was the only aspect of Arizona’s crackdown that the Supreme Court upheld.

So: If the Supreme Court says that one state (Arizona) may pester federal immigration authorities with more information about detainees than they asked for, can another state (California) deny the feds information they might seek?

It probably makes little difference in practice. Washington doesn’t have to investigate or deport anyone, no matter how much Arizona insists; and, at Brown’s insistence, California’s law still allows police to detain the most violent and dangerous people at the top of ICE’s priority list. In that sense, California’s law may be more symbol than substance.

Yet the issue it raises — the precise boundaries of federal and state discretion over the noncitizens in our midst — is not going away.

In rebelling against Secure Communities, California’s ruling liberal Democrats have availed themselves of a states’ rights concept similar to the one invoked by sheriffs from rural Montana and Arizona who resisted federal gun control laws during the Clinton administration.

In that case, Printz v. U.S., the sheriffs balked at a federal law requiring them to help carry out background checks of gun purchasers. By a 5-4 vote, the Supreme Court sided with the sheriffs, with Justice Antonin Scalia writing that Congress cannot “commandeer” state and local officials to carry out federal programs.

In declaring ICE “holds” purely voluntary in California even before the new law passed, California Attorney General Kamala D. Harris invoked Scalia’s Printz opinion as well as the tea party’s favorite constitutional amendment, the Tenth.

States’ rights makes strange bedfellows, it would appear. We shall see if anyone challenges California’s new laws in federal court and what position the Obama administration takes — though, because they are permissive by nature, it’s not clear how the California laws could produce a victim with the requisite legal standing.

Meanwhile, ponder Americans’ deep divisions over who can and cannot stay in this country and how far we are from the ideal articulated by Justice Kennedy. These decisions, he wrote, “must be made with one voice.”

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