BOSTON (AP) — The state’s newest U.S. Senator — William ‘‘Mo’’ Cowan — has been sworn into office by Vice President Joe Biden.
Cowan will serve on an interim basis, filling the seat left vacant by the departure of former U.S. Sen. John Kerry to become secretary of state.
Cowan took his oath of office at noon Thursday in Washington on the floor of the Senate.
Cowan was flanked on one side by Kerry and the other side by U.S. Sen. Elizabeth Warren.
Cowan’s tenure as senator will be brief. He will serve until Massachusetts voters can pick a replacement in a June 25 special election.
Cowan was tapped by Democratic Gov. Deval Patrick to temporarily fill the seat.
Cowan has said he will not run in the special election.