The lawsuit was filed on Monday seeking to block Mr Trump acting on his emergency declaration to build the wall. The US states arue the president does not have the power to divert funds approved by Congress to pay for his project.
“We’re suing President Trump to stop him from unilaterally robbing taxpayer funds lawfully set aside by Congress for the people of our states. For most of us, the office of the presidency is not a place for theatre,” California Attorney General Xavier Becerra said.
Joining California in the lawsuit were Colorado, Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Minnesota, Nevada, New Jersey, New Mexico, New York, Oregon, Virginia and Michigan.
All states but Maryland are governed by Democrats. They argue that President Trump’s order to divert funds would cost them millions of dollars, damaging their economies.
The lawsuit was filed in the court for the Northern District of California. The White House has not commented.
California Governor Gavin Newsom dismissed the president’s decision as “political theatre” while New York state’s Democratic Attorney General Letitia James promised to “fight back with every legal tool at our disposal”.