Vice President Mike Pence places a flag at a headstone as members of the Army 3d U.S. Infantry Regiment, The Old Guard, honor the nation’s falle

Vice President Mike Pence places a flag at a headstone as members of the Army 3d U.S. Infantry Regiment, The Old Guard, honor the nation's fallen military heroes during its annual Flags In ceremony at Arlington National Cemetery, Thursday, May 24, 2018, in Arlington, Va.(AP Photo/Cliff Owen)

Vice President Mike Pence places a flag at a headstone as members of the Army 3d U.S. Infantry Regiment, The Old Guard, honor the nation’s fallen military heroes during its annual Flags In ceremony at Arlington National Cemetery, Thursday, May 24, 2018, in Arlington, Va.(AP Photo/Cliff Owen)