Marc Thiessen’s enthusiasm for Scott Walker  is making him delirious:
A victory tomorrow would make Walker the instant front-runner for the GOP vice presidential nod.
Choosing Walker as the VP nominee would be just the sort of desperate short-term political maneuver that the Romney campaign is supposed to be trying to avoid in its selection process. Is Walker qualified to be next in line to the Presidency after just two years in statewide office? No, he isn’t. Romney has no foreign policy experience to speak of, and adding Walker to the ticket would do nothing to balance this. Walker’s record does not compare favorably to those of many of the other possible VP nominees. Selecting him would be a transparent attempt to generate enthusiasm and interest in the Republican ticket with no thought for his ability to serve as President if necessary.
Assuming Walker wins as expected , he would also bring significant baggage with him as a possible running mate. Whatever other political advantages Walker might theoretically have to offer, it usually isn’t a good idea to choose someone with any hint of scandal  associated with him. Politically, it doesn’t matter whether Walker has done anything wrong or not. Questions about Walker’s aides would be an ongoing distraction for the campaign. If it turns out that Walker is implicated in some wrongdoing, his presence on the ticket would become an instant liability. Romney would be widely perceived to have blundered in one of the more significant decisions of his campaign. Putting Walker on the ticket is a good example of a high-risk, low-reward move, and it doesn’t seem likely that Romney would do that.
Update: Charles Pierce reports  on the criminal case against one of Walker’s closest aides, Tim Russell:
If convicted, Russell is looking at 10 years in prison and $50,000 worth of fines. Courthouse sources say that the prosecutors are using these charges — on which Russell appears to be in serious danger of being convicted — to leverage testimony from him about what he knows regarding Walker and the John Doe investigation, which concerns Walker’s alleged use of his job as county executive for campaign and other political purposes. What Russell knows is presumed to be considerable and more than a few people around the case believe that, if Russell should flip on his boss, that would pretty much be the ballgame. Walker would have to start drawing on the $100,000 he’s got in his criminal defense fund. There is nothing that Scott Walker has done that Tim Russell doesn’t know about.
Read more about the John Doe investigation here .