Ezra Klein makes the good point that, no matter how things turn out in Wisconsin, unions have made the point that eliminating collective bargaining is going to be far more pain than it’s worth. That’s why Scott in Florida and Daniels in Indiana are running away.
As the poll shows, like a lot of other principles, collective bargaining is popular in the abstract, probably because it’s considered a fundamental right. It’s just dumb politics to attempt to punish your political opponents by removing a fundamental right a few weeks after taking office. It makes you look small and petty, and it also makes your allies (like police unions) wonder if they’re next. Walker may die on this hill, but nobody else is following him up.