Kerry Interview On Benghazi

The Washington Times  says that John Kerry will testify to the Select Committee on the Benghazi attack.
Who cares? His testimony will be of no consequence. He was not Secretary of State at the time. He was not in Benghazi. He was not in the War Office of Washington during it. The only thing that he knows will be what he has been told by people of the State Department and others in the Obama Administration.
Why not interview the White House janitor. He was at least there at the time and may know more.