On Tuesday, the Supreme Court handed down a decision that had far-reaching consequences – consequences that were missed entirely by the mainstream media. In Kansas v. Garcia, the Court held by a 5-4 vote that federal law did not prevent Kansas from criminally prosecuting illegal aliens for identity theft.

The Kansas law had been used to prosecute three illegal aliens who had stolen the social security numbers of other people. The five conservative justices voted to overturn a decision by the liberal-dominated Kansas Supreme Court.

For decades, the ACLU and other liberal attorneys have been pushing the theory that any time Congress passes a law in an area, any state law in the same area that can somehow be imagined to differ with the purposes of Congress is pre-empted and invalid. Using the phrase “purposes and objectives of Congress” pre-emption, they invite activist judges to muse about policy and to strike down state laws that contrast with the unstated policy objectives of Congress. Never mind that the purpose of a law is often unstated. And the 535 members of Congress may have 535 different reasons for their votes.

Although the Supremacy Clause of the Constitution makes clear that Congress can expressly declare that certain state laws are invalid, the notion that state laws can be invalidated without any express action by Congress is on weaker constitutional footing. It invites judges to do the pre-empting on behalf of Congress.

In the past seventy years, dozens of state laws have been swept away in this manner, without any clear statement from Congress. This has given constitutionalists and conservatives pause. As Justice Clarence Thomas has explained, the Founding Fathers certainly never intended that federal judges could take it upon themselves to speculate about what the purposes of Congress were, and then strike down state laws that are in tension with those purposes. According to Thomas, this theory “impermissibly rests on judicial guesswork about broad federal policy objectives.”

The ACLU has used this theory with particular enthusiasm in trying to prevent cities and states from assisting the federal government in immigration enforcement. As an attorney representing those cities and states, I have argued against them in many federal courts.

The liberal claim is that whenever there is an overlap between state and federal law affecting illegal aliens, and the purposes of the state legislature and Congress might have been somewhat different, the state law is invalid. In Kansas v. Garcia, liberal attorneys argued that federal immigration law overlaps with state laws against identity theft, and therefore such state laws must be invalid.

Writing for the majority, Justice Alito rejected this argument emphatically:

“The mere fact that state laws like the Kansas provisions at issue overlap to some degree with federal criminal provisions does not even begin to make a case for conflict preemption. From the beginning of our country, criminal law enforcement has been primarily a responsibility of the States, and that remains true today. In recent times, the reach of federal criminal law has expanded, and there are now many instances in which a prosecution for a particular course of conduct could be brought by either federal or state prosecutors. Our federal system would be turned upside down if we were to hold that federal criminal law preempts state law whenever they overlap, and there is no basis for inferring that federal criminal statutes preempt state laws whenever they overlap.”

These words will be quoted many times in the future by lawyers defending the validity of state laws. Not just in the identity theft and immigration fields, but in all areas. Challenged state laws will stand a much greater chance of surviving judicial review.

The Court stopped short of rejecting “purposes and objectives” pre-emption in its entirety. But Justices Thomas and Gorsuch wrote a separate concurring opinion arguing that the theory should be abandoned. Hopefully, more justices will join them in future cases.

Regardless the majority holding will have nationwide consequences in the immigration field for years to come. States can, and should, take steps to discourage illegal immigration. Tuesday’s decision will make it harder for liberal attorneys and judges to stop them.

Kris W. Kobach served as the Secretary of State of Kansas during 2011-2019. He was a professor of constitutional law at UMKC Law School during 1996-2011. An expert in immigration law and policy, he coauthored the Arizona SB-1070 immigration law and represented in federal court the 10 ICE agents who sued to stop Obama’s 2012 DACA executive amnesty. He is currently a candidate for the U.S. Senate. His website is www.kriskobach.com.