7 points down in a state that Obama won by almost 18 isn't bad, but then again it is an off year election. Mitt Romney got 1.5M votes last year and lost huge, Christie gets 1.3M and wins even bigger.
Bottom line in a CLinton v Christie general election I dont see NJ being a tipping point state, but I suspect that both parties would spend money there.
That is about the difference between a Favorite Son and an outsider. Contrast California between 1976 and 1980 and between 1984 and 1988, Georgia between 1972 and 1976 and 1980 and 1984, Texas between 1996 and 2000 and between 2004 and 2008. It may not apply so strongly to a near-max-out scenario (Illinois between 2004 and 2008). At this point I predict that Hillary Clinton will not defeat Chris Christie by a double-digit margin in Illinois.
The most likely tipping-point state in 2016 now looks like Pennsylvania or Virginia.