Plinko
Wildcard berths that can't beat teams without a winning record should have homefield advantage
Scott Walker hasn't declared for President.
Like Kasich and Christie he's in the nebulous zone regarding the difference between an actual campaign and having a PAC as sitting Governors.
Jindal's pulling the trigger this week because he's dead in all the relevant polls (national/Iowa/NH) and thus is currently outside the debate thresholds. Plus there's a governor's race this year so he's done while Christie, Kasich and Walker all have their second terms to go basically with Christie slightly ahead by a year.
As long as Walker leads Iowa and is in the top of the heap elsewhere he can hold off like Perry did in 2012. He probably shouldn't have back surgery and self-medicate though.
I still think Jeb wipes the floor with him in the debates. Jeb is going to be this cycle's Romney: He's going to be the only guy that appears reasonable, the carnival of crazy will die down, and republicans will realize Jeb is the only shot they have and get in lockstep behind him.
The difference between Jeb and Walker is that Jeb actually has a decent economic record, while Walker has an absolutely disastrous record in Wisconsin. When the general public finally sees what he did to that state he'll have absolutely zero shot at the presidency.