The Pentagon indicated that it's investigating Democratic Sen. Mark Kelly of Arizona, a former U.S. Navy captain, for a video that said service members should "refuse illegal orders."

The FBI is investigating Arizona Sen. Mark Kelly and five other Democratic lawmakers for urging military personnel to reject illegal orders. President Trump called their comments “seditious” and “punishable by DEATH!

Sen. Mark Kelly was pressed on whether he'd refuse military orders if he was still in uniform, after the Democratic lawmaker urged troops to disobey "illegal" orders from the Trump administration.

"He runs around on a stage, talking about lethality and warrior ethos and killing people," the Kelly said of Hegseth.

Defense Secretary Pete Hegseth speaks during the Northeast Indiana Defense Summit at Purdue University Fort Wayne on Nov. 12 in Indiana. (Darron Cummings/AP) If you’re a law-abiding citizen and someone admonishes you that robbing banks is a crime, you ...

Mark Kelly and five other Democratic lawmakers with military or intelligence backgrounds posted videos about troops disobeying illegal orders.

Kelly, a retired U.S. Navy captain, also has the standing to go to federal court if he is recalled to active duty to then be court martialed, said Rachel VanLandingham, a professor at Southwestern Law School and former Air Force lawyer.

The Dept. of War's investigation of Mark Kelly raises questions about the free speech rights of a sitting U.S. senator and retired Navy captain.