Thompson also said he does not support right-to-work legislation, another proposal popular with fiscal conservatives.
"I think that right now we do not need any further deterioration of labor-management relationships in Wisconsin. And I'll leave it at that," he said.
He also broke with Walker's decision to reject $810 million in federal funding for a high-speed rail
line between Milwaukee and Wisconsin. Walker turned down the money because he said it would cost the state too much to maintain the rail system. But Thompson said he would have accepted the money, albeit while tweaking some of the details of the deal.
After the event, the Thompson campaign sent out a release saying the high-speed rail comments were "misinterpreted." But the damage may have already been done: the Club for Growth sent out a release on Monday seizing on the high-speed rail issue.
Thompson's move away from Walker on these issues is a head-scratcher in the context of his campaign for the GOP nomination. Walker's policies may have infuriated the left, but the governor remains very popular among the conservative base of the Wisconsin Republican Party -- the same folks who tend to turn out in high numbers in Republican primaries.
With conservative activists rallying around Walker in the face of a likely recall election, Republicans in the Senate race have tried to cast themselves as lockstep Walker supporters in his battle with the left. State House Speaker Jeff Fitzgerald
his campaign pitch on the fact that he shepherded Walker's conservative agenda through the state legislature. Even former Rep. Mark Neumann
, who lost a bitter primary battle to Walker last year in the gubernatorial race, has positioned himself as a Walker ally: Neumann was the closing speaker at Saturday's pro-Walker rally.
It would be a questionable decision for any Republican running for statewide office to criticize Walker, but the choice is doubly confounding coming from Thompson. The former governor has been besieged with attacks from the right since announcing his intentions to run for Senate. Conservative groups like the Club for Growth have characterized Thompson as out of step with the modern day conservative movement.
Thompson has fought back against these criticisms, insisting that his record as governor stands up to scrutiny from the right. But he didn't do himself any favors on Monday. While opponents previously had to cite Thompson's past positions to paint him as a moderate, they can now point to fresh quotes from a Thompson campaign appearance in which he takes issue with part of Walker's agenda and fails to fully embrace the all-important collective bargaining restrictions.