I'm starting to fear Bernie's strong numbers, but I think we can beat Hillary no problem.
This poll suggests that Hillary Clinton could be collapsing. I saw a story (if in an unreliable source, the National Enquirer) that she has problems of health. If the story is true, then her health could tear her campaign apart. Marquette University Law School has one of the more reliable single-state polls.
Republicans can win the Presidency without Wisconsin (as they did in 2000 and 2004), but in both cases they barely lost the state. Republicans losing Wisconsin by 5% or more will lose the overall popular vote by at least enough that they cannot win the Electoral College contest. Sanders may be an unusually-good match for Wisconsin Democrats... but I have said that of New Hampshire, which also has been seen as a swing state.
I not only heard about the National Enquirer story, but read it, and put up a thread about it, and then was flamed to death by the usual suspects. Now it's your turn. Enjoy.