The new CBS poll has Biden up in Wisconsin by 6. Why is this?
white college voters: Biden +13
white noncollege voters: Biden -10
Biden today relative to Clinton 2016:
white college voters: +1
white noncollege voters: +8
We project that white noncollege voters will be 55 percent of all WI voters in 2020, compared to 34 percent for white college voters.
Conclusion: Biden's improved performance among white noncollege voters is primarily--overwhelmingly--responsible for his current lead in the state.
As a final thought, look at the table below on WI voters' reaction to a question on whether protesters in US cities are trying to act peacefully. The potential problem is easy to see.