Doesn’t MI and WI have GOP governors and legislatures? In that case, it may not be much of a shock.
We saw a dramatic late shift in last year’s Canadian federal election, which was a 3 party race. The governing Conservatives hovered in the low 30s most of the campaign period but never went below 30% in the polls, which is where they ended up. But the two opposition parties switched places entirely. Early in the race the ultra socialist NDP were leading and the soclialist-lite Liberals were in 3rd. Then momentum shifted and the Liberals surged entirely at the expense of the NDP. There had been a high degree of “undecided” up to that point, and when they broke in the week prior to the election they went en masse for the Liberals.
It looks as though the same thing is happening now. The undecideds who had parked their votes with Johnson or Stein are now shifting massively for Trump. What had been a tight race could turn into a rout.