I live in New Jersey. I'll say this: Don't read too much into it. I know many people (including myself) that are either independents or democrats that voted for Christie. Sorry to burst your Republican bubble - we are not big fans of Christie or the Republican party. We are not Republicans nor are we becoming Republicans, especially not the Southern Fundamentalist type. Given the current situation we just hate incumbents. The Goldman Sachs thing as well as Corzine buying the past elections also finally rubbed us the wrong way. And if this recession/depression lingers, which I think it will, many incumbents will have a tough time. And that's a good thing. By the way - I voted against ALL incumbents, so basically, my votes for municipal and county offices were split between the parties.
Using YOUR logic, if there are more democrat incumbents, and voters like you will vote against incumbents, then republicans would benefit.