More than 500 law firms moved to file an amicus brief in support of Perkins Coie's lawsuit against the Trump administration's executive order that targeted the firm.

The firms signed a legal brief supporting Perkins Coie, calling the president’s actions a threat “to the rule of law.” The largest firms declined to sign.

The filing backed a lawsuit that Perkins Coie, a firm founded in Seattle, filed on March 11 to block Trump's executive order issued against the firm over its diversity policies and its prior legal work for the campaign of Democrat Hillary Clinton, his opponent in the 2016 presidential election.