Party primaries were held on September 14, though all four candidates ran unopposed in their respective primaries.Tim Murray, who ran on a ticket with Patrick, was re-elected Lieutenant Governor. As of 2018, this is the most recent election in which a Democrat was elected Governor of Massachusetts.
Running mate: Richard P. Purcell, surgery clerk and ergonomics assessor
Defection of Loscocco
On October 1, 2010, Loscocco announced that he would withdraw from the race and endorse Republican candidate Charlie Baker. Loscocco formally remained on the ballot, however. On October 7, Cahill filed a lawsuit against four former campaign aides, alleging that they conspired to undermine his candidacy and help Charlie Baker by arranging his defection. Cahill claimed that e-mails between Republican political consultants and Loscocco's top aide suggested that Loscocco may have been enticed to leave the ticket by future job promises. In response, Loscocco claimed that Cahill's top aide was coordinating strategy with the Patrick campaign and the Democratic Governors' Association and thus was never actually an independent effort.
Soon after Cahill filed suit against him, Adam Meldrum, Cahill's former campaign manager, alleged that Cahill colluded with the Massachusetts Lottery, which is overseen by the state treasurer's office, to run an ad favorable to him during the campaign. The ad, paid for by the Commonwealth, described the Massachusetts Lottery "the most successful state lottery America" and "consistently well-managed", echoing themes from Cahill's gubernatorial campaign. Both Cahill and Massachusetts Lottery Director Mark Cavanagh denied the allegations. On October 18, e-mails released in conjunction with Cahill's lawsuit appeared to reveal that the campaign attempted to have the Lottery air a series of ads that praised the lottery's management. In the e-mails, Cahill's campaign media strategist Dane Strother told Meldrum to "Get the Lottery immediately cutting a spot and get it up...Needs to focus on the Lottery being the best in the country and above reproach." Two days later, Cahill's senior adviser Scott Campbell wrote, "I think the first thing is to figure out what/where/how we want to do this ... with Lottery people."
On April 2, 2012, Cahill was indicted by a Grand Jury on charges that he used $1.65 million in Massachusetts State Lottery advertising to aid his campaign for governor. On December 12, 2012, a mistrial was declared in the corruption case after the jury failed to reach a verdict on two counts of conspiracy.