DENVER (AP) — Colorado is joining with California and other states in challenging President Donald Trump’s emergency declaration to fund a wall on the U.S.-Mexico border.

In a joint statement Monday, Gov. Jared Polis and Attorney General Phil Weiser said they decided to join the effort in part because tens of millions of dollars could be diverted from military construction projects in Colorado to build a border wall.

“In this action, we are fighting for Colorado’s interests and defending the rule of law,” the two Democrats, who took office last month, said.

The Colorado Springs area is home to several large military installations, including Fort Carson, the Air Force Academy and Peterson Air Force Base, the home of U.S. Northern Command which is responsible for homeland defense. Besides providing for the nation’s defense, Polis and Weiser said Colorado’s military facilities are important economic drivers.

The announcement came on the same day protesters gathered in frigid weather at the state Capitol to protest the emergency declaration. Denverite reported the crowd of more than 100 people roared with approval when Weiser told them his office was joining the multistate lawsuit challenging Trump’s action.

On Friday, Polis called Trump’s plan to bypass Congress to spend more money on a border wall “an astonishing abuse of power.”