Wouldn't be so sure... If this holds until election day we could be seeing a Ron Johnson situation again.
I'm not denying that Walker could win, but is this really an apt comparison? Virtually no one outside of Atlas has been writing Walker off as dead (most pundits thought he was heavily favored until pretty recently), and most think this race is a Toss-Up. Also, given what's happened since 2016, I'm not inclined to think that undecided voters and Independents will break very heavily Republican. Again, he's definitely still in the race, but I don't see the parallel.