Bernie Sanders: 48%
Hillary Clinton: 43%
So PPP, Fox, and Marquette are basically in agreement here.
Overall, this is both very good, and pretty bad, for Sanders. In terms of momentum/optics/fundraising, a win in Wisconsin will allow him to go into NY with "the wind at his back" However, it would also be a clear loss in terms of delegate goals. Unlike the West Coast Caucuses, he won't meet his delegate target with a 5 point win. It would also suggest that the fundamentals of the race remain unchanged, and that he won't win NY, PA, NJ, MD, DE, CT, PR or CA. Hillary will extend her delegate lead to probably 400-500 pledged delegates after June 7. Then, the party will expect him to graciously concede.