A report in the New York Post suggests that New Jersey Governor Chris Christie, who will deliver Tuesday's keynote at the Republican National Convention, is not confident of the nominee's chances. According to unnamed sources, Romney's campaign would have insisted that Christie resign as governor in order to run for vice president, but that Christie refused because he didn't think they could win.

The story doesn't say that Christie was formally offered the job or that he was even the number one choice, but the resignation was apparently a prerequisite for any offer to join the ticket. The fear was that if he remained in his day job, the campaign would not be able to accept donations from Wall Street banks that do business in New Jersey. Yet, the Post says that despite being pushed to take the job, "Chris knows the score" and wasn't willing to sacrifice his position to join a losing effort.

It isn't so unusual to hear these anonymous excuses for why someone didn't make a presidential ticket, but the timing is certainly interesting, given that Christie is set to headline his party's convention tomorrow night. Why either side would seek to undercut the team spirit just before the man goes on TV to sing Mitt's praises in anybody's guess. (The same goes for this story carping on Romney's foreign policy team in National Journal.) Presuming the leak from someone in the know — someone close to Christie — it also underscores his biggest weakness as a running mate: He just can't help himself.

UPDATE: 11:00 a.m.: Advisers for both Christie and Romney are denying the Post report, telling NJ.com that it is crazy to suggest Christie thought Romney would lose. However, when asked whether Christie refused to resign in order to join the ticket, his adviser said to talk to Romney's people. They had no comment.