Really, the only way Corzine loses in '05 is if he gets hit with some large scandal--in which case he might as well not bother running for re-election in '06...
I suppose.
I agree. If Corzine loses for whatever reason, his Senate seat will not be safe even if he runs again for it. I'd say the Senate seat is "slight open Dem" at this time because
1) NJ's natural tilt towards the Dems
2) Corzine (assuming he wins Gov election) will essentially appoint the Democratic nominee and they will have a year of incumbency at the time of election.
However, with that being said Kean Jr. is a pretty strong candidate for the GOP which prevents this race from being lean, or even safe Democrat.