Santorum Leads in Michigan, Lampooned in Media

Rick Santorum is seeing more people start to move in his direction.  In a recent poll in the State of Michigan, he leads Mitt Romney 33-27 percent among Republican voters there.  In the meantime, he appeared on NBC's Meet the Press and was asked some questions about his stand on women in the military and working mothers.  The questions seemed to be a little outside the realm of good taste.

Do these things show that Santorum is a credible candidate or is he still on the fringe?