 In 2012, McMullen was the Republican nominee for Vermont Attorney General, and faced Democrat William Sorrell, the longtime incumbent, who was running for his eighth two-year term.Sorrell survived a close primary election against T. J. Donovan, and defeated McMullen in the general election with 58 percent of the vote to McMullen's 33, with the rest going to Progressive and Liberty Union candidates.McMullen continued his business career after moving to Vermont, and resided in Burlington.