A group of 20 states is suing the U.S. Dept. of Transportation and Secretary Sean Duffy over new requirements to cooperate with U.S. Immigration and Customs Enforcement or have their transportation grants terminated.

The dispute stems from a letter Duffy sent to federal transportation funding recipients in April warning that the monies could be canceled if awardees set diversity, equity and inclusion goals or fail to cooperate with immigration enforcement. Attorneys general from the states said in their complaint, which was filed in federal court in Rhode Island May 13, that DOT officials have already begun including requirements in funding agreements. 

“As recipients of such DOT funds, you have entered into legally enforceable agreements with the United States government and are obligated to comply fully with all applicable federal laws and regulations,” Duffy wrote.

Imposing the immigration enforcement requirements exceeds DOT authority, the states argue, because they were not added by Congress as a condition to receive funding. Also they claim, immigration enforcement is unrelated to the transportation and infrastructure funding programs in question. 

Duffy has made a similar point in explaining his removal of requirements related to Biden-era environmental and social justice initiatives from grant agreements—emphasizing that those provisions had not been included by Congress in their funding packages. DOT has not yet responded to the suit, and department representatives did not immediately comment on the case. 

The state attorneys general say the condition is vague as written and could be broadly interpreted as requiring their law enforcement or other staff to participate in federal immigration enforcement, forcing states to pay related administrative costs and adding burdens on their limited personnel, who may have no expertise in immigration enforcement. That could also expose states to civil liability in connection with their acts related to federal immigration enforcement, state officials wrote in their complaint. 

“Let’s be clear about what’s happening here: the president is threatening to yank funds to improve our roads, keep our planes in the air, prepare for emergencies, and protect against terrorist attacks if states do not fall in line with his demands,” California Attorney General Rob Bonta said in a statement. “He’s treating these funds, which have nothing to do with immigration enforcement and everything to do with the safety of our communities, as a bargaining chip.”

States participating in the suit include California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, Nevada, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, Washington and Wisconsin—all with Democrat-led administrations or a Democrat as attorney general.

They want the Rhode Island court to declare the immigration enforcement requirements unconstitutional and to block DOT from implementing or enforcing it.them. The same states also filed a separate lawsuit against the U.S. Dept. of Homeland Security over similar issues.