I don't like drawing conclusions about the national electorate from NY-23 any more than I do from the gubernatorial races in NJ and VA. 

I tend to agree with Nate Silver that the lesson of last night should be "All Politics is Local".  We can draw conclusions about national trends next year when there are 435 local elections across all 50 states.

Hoffman didn't live in NY-23 and showed no knowledge or interest in local issues.  Ninety-five percent of his funding was from outside of the district.  

Corzine was up against a bad economy.  According the Silver "three-quarters of Corzine's voters cited a national issue -- health care or the economy -- as their primary reason for voting for him, two-thirds of Christie's picked a local one (property taxes and corruption)."