Sorry, California Democrats, but you have already lost the battle over stopping President-elect Trump’s immigration policies.  You lost five years ago when the state of Arizona tried, as sanctuary cities are doing now, to upend federal immigration laws, and the US Supreme Court said no.

In 2010, Arizona Gov. Jan Brewer signed into law SB 1070, a law that made it illegal to be an undocumented immigrant in Arizona and in essence allowed the state to enforce immigration laws.  Supporters insisted the Obama Administration was doing too little to protect the borders, so the state had to step in.

While now the shoe is clearly on the other foot, efforts by California Democrats to somehow frustrate a Trump Administration immigrant policy have more than faint echo of the Arizona law, since both involve an attempted nullification of federal law.  That issue is well settled, and Democratic leaders are not going to stop Trump’s interpretation and enforcement of the law.

That’s because the same people who are now hysterical over Trump took Arizona all the way to Supreme Court and won a big victory for federal control of immigration policy.

The court considered four provision of SB 1070 and struck down three of them: making it a crime to be in the country illegally, a ban on undocumented immigrants applying for a job or working in the state, and warrantless arrests of persons thought to have committed a deportable crime.  The court said all three of these provisions are entirely preempted by federal law and cannot be enforced by the state.

The only provision the court upheld was one allowing the police to check the immigration status of persons they detain before releasing them.  The court found that this did not conflict with anything in federal law, so could remain in effect.

The opinion, written by Justice Anthony Kennedy, contains quite strong wording  on the federal government’s pre-emption of border security and immigration law, with language like “the federal government has occupied the field of alien registration” and “even complementary state regulation is impermissible,” that the law was an “obstacle to the full purposes and objectives of congress,” and that immigration enforcement is “entrusted to the discretion of the federal government.”

The hopes of Democrats that legislative leaders or new Attorney General Xavier Becerra are going to lead some crusade against Trump’s power to enforce the law as he sees fit is going to run right up against the Supreme Court in the Arizona case.  As Solicitor General Donald Verrilli said at the time, “the states are trying to supplant the federal government’s role in setting immigration policy and we can’t have fifty different immigrant policies.”

An early test of all this could come if President Trump tries to defund so called “sanctuary cities” that are refusing to enforce immigration law.  While there is no affirmative requirement of cities to enforce immigration law – it is truly the purview of the federal government – neither can cities frustrate the government’s enforcement powers.

The Arizona case also nullifies any attempt of sanctuary cities, universities or anyone else, to stop federal deportation policies.  Should the Trump Administration attempt to cut off federal funds for sanctuary cities, as he has said he will do, prevailing constitutional law certainly favors his position.

Perhaps all this will end up being a tempest in a teapot.  Trump will surely revoke President Obama’s executive order legalizing several million undocumented immigrants; but this is currently on hold before the Supreme Court.  More difficult would be an effort to repeal the “Dreamers law”(Deferred Action for Childhood Arrivals) that allows about 700,000 young people brought here illegally as children to remain as long they do not violate the law.  Trump has shown some sympathy for this program.

Apprehensions at the border are way down, suggesting the vast flow of illegals into the American southwest may be past, especially as the economy of Mexico improves and there are fewer low skill jobs on this side of the border.  And about 40 percent of illegal aliens in the United States came here legally and have overstayed their visas.  These now illegal immigrants are also the most likely to commit terrorism, not farm workers crossing the Mexican border.

So it would make sense for Democratic leaders to seek some accommodation with Trump; he says he wants to concentrate on deporting those who have committed crimes (already the Obama policy).  And the Democrats would do well to acknowledge how weak their hand is if they try to frustrate enforcement of federal immigration policies.