A federal judge just shot down a move by the U.S. Department of Transportation (USDOT) to force states to help enforce federal immigration law or risk losing their transportation funding.

The big picture: In a decision from November 4, Judge John McConnell said USDOT went too far by threatening to withhold money from states that did not work with agencies like Immigration and Customs Enforcement (ICE).

• The policy in question, called the "Duffy Directive," was put out back in April 2025. It told states they had to cooperate with immigration enforcement to keep their federal transportation grants.
• Twenty states, including California, Illinois, New York, and several others, sued, arguing USDOT doesn’t have the legal power to set these sorts of conditions.
• The court agreed, saying the Constitution does not allow the DOT to force states into assisting on civil immigration enforcement just to receive government dollars.

What the judge said: Judge McConnell called USDOT’s move "lawless behavior" and said it overstepped the limits set by Congress and the Constitution, according to court records.

The ruling means DOT can’t use federal grant money as a way to make states follow federal immigration priorities.