, I thought he was heavily favored!
Walker has a low ceiling and a high floor, and that would make this race semi-contentious no matter who the Democrats run (hell, they could run freaking Barrett again and he'd still get probably 45% of the vote in the end).
Because he's a very polarizing politician. His positions the issues, particularly on labor unions have simultaneously endeared him to conservatives and made liberals infuriated with him. Thus, you have a lot of people in Wisconsin who are very likely to vote for him and very likely to vote against him, with relatively few swing voters.
Anyways, it will be interesting to see how this race shapes up.
