Jill Stein, physician and co-chairperson of the Green-Rainbow Party, declared her candidacy on January 7, 2010. Her running mate was Richard P. Purcell, a surgery clerk and ergonomics assessor, of Holyoke.
Tim Cahill, State Treasurer and Receiver-General. Cahill had won the 2006 treasurer's election as a Democrat, but changed his party to "unenrolled" (equivalent to "independent" in Massachusetts) so he could challenge Patrick in this election. Paul Loscocco, a former Republican State Representative, was his running mate.
Ahead of the April 2010 Republican party convention, many delegates preferred Harvard Pilgrim CEO Charlie Baker to be the Republican nominee, however, there was support for State SenatorBob Hedlund, former State Treasurer Joseph D. Malone (who declined to instead run for Congress), and former Lieutenant Governor Kerry Healey. In early 2009, two "draft" websites appeared encouraging Baker and U.S. AttorneyMichael Sullivan to run for governor. Christy Mihos announced his bid for governor on April 25, 2009 as a Republican; in 2006 he ran as an independent. Baker announced his candidacy on July 8, 2009, and went on to win the nomination at the state Republican Party convention, freeing him of a primary challenge from Christy Mihos, with 89 percent of the vote.Richard R. Tisei was Baker's running mate.
On June 1, 2010, Ross withdrew from the race when she could not garner the amount of signatures needed to run, leaving Patrick as the only candidate in the primary race going into the June 5 Democratic State Convention. Incumbent Lieutenant GovernorTim Murray was again his running mate.
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.