The Supremacy Clause of the Constitution makes it explicitly clear that federal law is the supreme law of the land, but the federal government doesn't have a law for everything.
The Trump regime recently challenged a California law that mandates state inspections of immigrant detention facilities used by the federal government and limits local law enforcement cooperation with immigration authorities.
Trump regime lawyers claimed the state law violates federal law, but the judge wrote that there is no federal law against it.
The twin rulings by Mendez, who was nominated to the federal bench by Republican President George W. Bush, allow California to continue limiting police cooperation with immigration officials and require inspections of detention facilities despite the Trump administration’s lawsuit filed in March. [...]
As for California’s law that requires state inspections of detention facilities where immigrants are held, the judge wrote that he found nothing in the federal statutes saying Congress did not intend for states to have oversight of detention facilities in their borders.
The law “does not give California a role in determining whether an immigrant should be detained or removed from the country, nor does it place any substantive requirements or burdens on these detention facilities apart from providing access,” Mendez wrote.
The California law also prohibits state employees from allowing immigration authorities on their property without a warrant. U.S District Judge John Mendez allowed the challenge of that provision to proceed. So, the state prevailed on 2 out of 3 claims.