Max Baucus is not running this year. John Tester is up for reelection. Looks like he might lose to Dennis Rehberg or state house member. Tester has never polled ahead of Rehberg yet. 
Don't get sucked in by the polls regardless of which side you are on compared to them. Fight for what you believe and do it for the person you support.
Polls are a powerful tool in elections and campaigns. First they tell the candidate if they are touching the right spots in voters, and we never see most of those polls because they are the truly balanced and accurate ones. Their main purpose is to skew the numbers in a way to encourage or discourage participation by your own side or the opposition. They are there to reinforce the people that want to vote for a winner, to build confidence you are on the right side, and even to show you are on the losing side so it doesn't pay to vote or maybe switch sides so you can claim to be a winner.
Ignore the polls, learn all you can about the candidates, and vote your values.