A primary election lets voters choose candidates for an upcoming election - in this case the 2010 mid-term elections on November 2nd. "Primaries" are carried out by the government on behalf of Republican and Democratic parties. Voters must declare affiliation with one party or the other. Third parties typically select their candidates through a means less formal that a voting primary.
U.S. Senate Race - NONENotes
In the race for governor, Mark Dayton played comeback kid, overcoming a personal battle to get back into politics. In a newspaper interview last year, Dayton - a recovering alcoholic - told a reporter that he takes medication for depression. He also said he started drinking before leaving the Senate in 2007 and that a stint in rehabilitation has helped keep him sober ever since.