I don't understand why Walker would be their pick after what he did in Wisconsin regarding his campaign finance issues. He and his Republican friends quickly & quietly disbanded the state GAB and replaced it with a partisan board for no good, legitimate reason. At the same time, he also quietly signed a bill loosening campaign finance restrictions. And iirc, there were also concerns about his State Supreme Court appointment(s). He could also be hit for helping rig the state maps in the last round of redistricting. This would be more potent if the current lawsuit against these rigged maps succeeds. Their trial wrapped up a week or two ago and the plaintiffs did make a good case.
Point is, if they plan to toss in a candidate at the last minute - One who will have little time to build up a viable campaign, Walker doesn't seem like the best option. Painting him as corrupt doesn't seem like it would be that hard.
Not to mention he completely flamed out of the race about 4 months before it even started
