Mo Cowan
@SenMoCowanWilliam Maurice Cowan is an American politician and lawyer who served as a United States Senator from Massachusetts from February 1, 2013, to July 16, 2013. A member of the Democratic Party, he previously served as legal counsel and chief of staff to Governor Deval Patrick. Patrick appointed him on an interim basis to fill the vacancy left by fellow Democrat John Kerry, who resigned to become U.S. Secretary of State. Wikipedia*
On the C-SPAN Networks:
Mo Cowan has 14 videos in the C-SPAN Video Library; the first appearance was a 2013 News Conference as a Chief of Staff for the Office of the Governor in Massachusetts.