Precinct caucuses convene around the state tonight (Tuesday). The caucuses are, in many ways, the kickoff to what's bound to be a big election year in Minnesota. The governor's office, two U.S. Senate seats, eight congressional seats and control of the state House are all up for grabs. Minnesota DFL Chairman Ken Martin and GOP Chairwoman Jennifer Carnahan answered questions from MPR News host Mike Mulcahy about what voters can expect if they turn out to caucus Tuesday night.