(Undated)  --  The first poll in the Minnesota governor's race suggests Republicans have the upper hand six months before Election Day.  The SurveyUSA Poll shows the GOP-endorsed candidate Tom Emmer as the frontrunner in three hypothetical races.  Emmer leads DFL-endorsee Margaret Anderson Kelliher 41 to 33 percent, he has a 42-34 advantage over Democratic primary challenger Mark Dayton, and a 42-31 edge over DFL candidate Matt Entenza.  The Independence Party's Tom Horner received between nine and ten percent of vote in the three matchups, while 15 to 17 percent are undecided.  Thirty-six percent of respondents identified themselves as Republicans, compared to 35 percent Democrat and 24 percent Independent.