Here’s what I want to get through your head: state and local police can enforce federal immigration law. Federal law does not prevent them from doing so.
Don’t take my word for it. Here are federal court opinions saying so:
In 1983, the United States Court of Appeals for the Ninth Circuit -- you read that right, the Ninth Circuit -- concluded, in Gonzales v. City of Peoria, 722 F.2d 468, that, “Although the regulation of immigration is unquestionably an exclusive federal power, it is clear that this power does not preempt every state activity affecting aliens.” Rather, when “state enforcement activities do not impair federal regulatory interests concurrent enforcement is authorized.” The Court accordingly held “that federal law does not preclude local enforcement of the criminal provisions” of federal immigration law.
In 1984, the United States Court of Appeals for the Tenth Circuit likewise ruled, in United States v. Salinas-Calderon, that “[a] state trooper has general investigatory authority to inquire into possible immigration violations.”
Fifteen years later, in 1999, the United States Court of Appeals for the Tenth Circuit reaffirmed its position, in United States v. Vasquez-Alvarez, 176 F.3rd 1294, stating, “this court has long held that state and local law enforcement officers are empowered to arrest for violations of federal law, as long as such arrest is authorized by state law.”
In 2001, the United States Court of Appeals for the Tenth Circuit ruled again, in United States v. Santana-Garcia, 264 F.3rd 1188, “that state law enforcement officers within the Tenth Circuit ‘have the general authority to investigate and make arrests for violations of federal immigration laws,’ and that federal law as currently written does nothing ‘to displace . . . state or local authority to arrest individuals violating federal immigration laws.’ On the contrary, the Court said, “federal law ‘evinces a clear invitation from Congress for state and local agencies to participate in the process of enforcing federal immigration laws.’”
In 2001, the United States Court of Appeals for the Eighth Circuit held, in United States v. Rodriguez-Arreola, 270 F.3rd 611, that a state trooper did not violate the defendant’s rights by questioning him about his immigration status after pulling him over for speeding.
In 2002, the United States Court of Appeals for the Tenth Circuit held, in United States v. Favela-Favela, 41 Fed. Appx. 185, that a state trooper did not violate the defendant’s rights by asking questions about his immigration status, after pulling the defendant over for a traffic violation and noticing there were 20 people in the van the defendant was driving.
In 2005, the United States Supreme Court held, in Muehler v. Mena, 544 U.S. 93, that police officers who handcuffed a gang member while they executed a search warrant for weapons, did not violate her rights by questioning her about her immigration status. The Court explained, “[E]ven when officers have no basis for suspecting a particular individual, they may generally ask questions of that individual; ask to examine the individual's identification; and request consent to search his or her luggage."
In 2005, the United States Court of Appeals for the Tenth Circuit confirmed again, in United States v. Hernandez-Dominguez, 1 Fed. Appx. 827, that "[a] state trooper [who has executed a lawful stop] has general investigatory authority to inquire into possible immigration violations."
in 2008, the United States District Court for the Eastern District of Missouri held, in Gray v. City of Valley Park, 2008 U.S. Dist LEXIS 7238, affirmed 2009 U.S. App. LEXIS 12075, that federal law did not preempt a local ordinance suspending the business license of any business that hires illegal aliens.
In 2008, the United States District Court for the District of New Jersey concluded, in Rojas v. City of New Brunswick, 2008 U.S. Dist. LEXIS 57974, that, “As a general matter, state and local law enforcement officers are not precluded from enforcing federal statutes. Where state enforcement activities do not impair federal regulatory interests concurrent enforcement activity is authorized.” The Court accordingly held that a city and its police department had authority to investigate and arrest people for possible violations of federal immigration laws.
I could go on and on, but you get the idea.
The people whose legal opinion matters are the men and women who wear black robes, and they have ruled, again and again and again that federal law lets local police enforce federal immigration law.