California Attorney General Xavier Becerra filed the lawsuit Wednesday, claiming the Trump administration is violating the U.S. Constitution.
Jeff Mateer, the current first assistant attorney general of Texas, was serving at the time as general counsel of the First Liberty Institute.
Each of the three has been outspoken about immigration reform in the U.S.
His reported absence would fit a trend of being less focused on diplomacy and more concerned about efficiency.
It's all about deregulation, deregulation, deregulation.
President Trump's personal lawyer Michael Cohen was set to have a closed Senate hearing. But after he spoke to the press, it was opened to the public.