The 2010 gubernatorial election saw an exceptionally large field of candidates seeking endorsement from each party's respective convention. In the DFL and the Independence Parties there were protracted primary fights that extended into August. The state's three major parties participated in the general election along with four minor parties.
After incumbent Governor Tim Pawlenty announced in June 2009 that he would not seek a third term, the field was open for Republicans to seek their party's endorsement. At the Minnesota GOP's off-year state convention in October 2009, former Representative Marty Seifert took first place in a straw poll with 37% of the vote. Representative Tom Emmer took second place with 23%, Patricia Anderson had 14%, and the rest of the participating candidates received less than 10% each.
Seifert had another victory in the February 2 precinct caucuses, winning a statewide straw poll of caucus attendees with 50% of the vote, followed by Emmer with 39%. None of the other candidates got beyond single digits. Delegates to the state convention, however, were more closely divided between Emmer and Seifert than the initial straw poll indicated. Both camps claimed a delegate lead throughout the process leading up to the state convention, but the outcome was uncertain and was ultimately decided on the convention floor.
On April 30, Emmer won the Republican endorsement at the party's state convention in Minneapolis. After Emmer won 56% of the vote on the second ballot, Seifert withdrew from the race and threw his support to Emmer. Emmer then chose Metropolitan Council member Annette Meeks as his running mate for lieutenant governor.
Emmer won the August 10 primary, earning a spot on the November ballot.
The list of candidates seeking the DFL's nomination was long going into the February 2 caucuses, with over 11 candidates having submitted their names for the candidate preference ballot. Former U.S. Senator Mark Dayton notably declined to be included on the ballot. Minneapolis Mayor R. T. Rybak won the straw poll with 21.8% of the vote, with State House Speaker Margaret Anderson Kelliher receiving 20.1%, and "uncommitted" receiving 14.7%. The other each candidates received single-digit support.
Former State Senator Steve Kelley dropped out of the race after a disappointing result in the straw poll. State Senator Tom Bakk also dropped out on March 20 after announcing at the St. Louis County Convention that he believed his chances of winning were slim.
On April 24, the DFL State Convention was held in Duluth. State Senator John Marty withdrew from the race after seeing lower than expected support on the first ballot, and State Representative Tom Rukavina withdrew after the fourth ballot, endorsing Kelliher. State Representative Paul Thissen withdrew after the fifth ballot, and before the results of the sixth ballot were announced, Rybak withdrew as well, endorsing Kelliher. Kelliher was subsequently endorsed by the convention. Ramsey County Attorney Susan Gaertner, who had not sought the DFL endorsement but was planning to run in the primary, dropped out two days later. That left Kelliher facing Dayton and former State House Minority Leader Matt Entenza in the August primary.
Shortly after the end of the 2010 legislative term, all three major DFL candidates had announced their choices for lieutenant governor. On May 21, Kelliher announced that John Gunyou would be her running mate. Gunyou is MinnetonkaCity Manager and was state finance commissioner in Republican Governor Arne Carlson's administration. On May 24, Dayton announced that Yvonne Prettner Solon as his running mate. Solon is a psychologist and three-term state senator. On May 27, Entenza announced that Robyne Robinson as his running mate. Robinson is a small-business owner and former TV anchor.
Dayton narrowly defeated Kelliher in the August 10 primary, earning the right to serve as his party's nominee. He was formally endorsed by the DFL on August 21.
Early polls showed Emmer even with his likely DFL opponents, with Horner trailing far behind, and a large percentage of voters undecided. As the race progressed, polls showed the candidates even, or Dayton with a small but significant lead. The nonpartisan Cook Political Report, CQ Politics and pollster Rasmussen Reports rated the gubernatorial election a tossup, while New York Times political statistician Nate Silver gave Dayton an 86% chance of winning and Emmer 14%.
Dayton led Emmer at the close of balloting by 8770 votes (0.42%). The margin of victory was small enough to trigger an automatic recount under state law, but analysts generally thought it unlikely that Dayton's lead would be overturned.
Dayton became just the fourth victorious Minnesota Democrat to win a gubernatorial election with a Democrat in the White House in 28 cycles.
Olmsted County, Minnesota officials recounting votes on November 29, 2010
The recount was carried out by the Minnesota Secretary of State, Mark Ritchie, as part of a State Canvassing Board, which consists of the secretary of state, two justices of the Minnesota Supreme Court, and two judges of a Minnesota district court. The vote totals were not significantly changed, and Dayton was declared the governor-elect.