I know -- you're flabbergasted.
Referring to the establishment of Congress, the Constitution says, "no Person holding any Office under the United States, shall be a Member of either House during his Continuance in Office." Yet there was Sen. Lindsey Graham, in Iraq, pistol in a shoulder holster, serving an elective two weeks of reserve duty as an Air Force Reserve colonel.
He didn't even have to read the Constitution to know he was violating it. The highest military court read it to him a year ago, when it found that he had violated the Constitution by serving as a military court judge while a Senator.
Obviously, there is a separation of powers problem with having a Senator under command of the President. And it's a clear violation of Article I of the Constitution -- just ask any strict constructionist. Like Lindsey Graham.