In 2006, Murray announced his intention to challenge Thibaudeau for the 43rd District seat in the State Senate. In May 2006, Thibaudeau dropped out and Murray was elected to the Senate with little opposition. He took his senate seat in January 2007. In his first session in the senate (2007–08), he was appointed vice chair of the majority caucus and in the 2009–10 session, he served as caucus chair, a post that largely is in charge of budget for the Senate and other housekeeping matters. After being reelected unopposed in 2010, Murray was appointed chair of the Ways & Means Committee for 2011–12.