key states. tonight, minnesota and wisconsin with key races in each of those states. but the eyes are on the midwest tonight where democrats are starting to undo what happened in 2016 and some of those battleground states, most notably the race for wisconsin governor where democrats have a crowded field. scott walker is running for the fourth time. they believe he may be vulnerable this time around. peter doocy has more background on what we should be watching tonight. >> eight democrats are elbowing each other out of the way for a chance to face governor scott walker. but national democrats have been having kind of a hard time figuring out which candidate they should help with early resources or endorsements. the front runner is seen as the state's education superintendent tony devers, but he's not necessarily a favorite of the