Knollenberg's district is still majority Republican, since he doesn't have most of the southern Oakland County communities that have been turning blue (largely due to migration from Detroit).

But the other factor that is turning Oakland County more blue is that these people are FISCAL conservatives who are a very poor match for today's GOP.  These are not social conservatives at all; back in the day, even as Oakland County gave Reagan huge majorities, I recall that Dr. Kevorkian enjoyed the support of the public by more than a 2-1 margin.  In fact, they even threw out the Republican county prosecutor for persecuting him so extensively.

Oakland County would still vote for a moderate, low-spending-low-taxes Republican every time.  But Knollenberg has signed onto the full wingnut agenda, and these are not people who support things like the Terri Schiavo debacle.  The real problem is the lack of Democratic infrastructure in what's long been a one-party area, but I maintain that Knollenberg is extremely vulnerable.