Why Rudy Giuliani blew apart in the 2008 Republican Primary:
1. Giuliani '08 was always a book tour. Never a presidential campaign. You have to play to stay.
2. 9/11 does not a message make. Especially in 2008.
3. Bernard Kerik.
4. National polls mean next to nothing in a Presidential Primary fight. Even if you want them to.
5. Candidate arrogance (with no real good reason).
6. Family/Spouse issues.
7. John McCain never went away.
8. Staff arrogance (with absolutely no good reason)
9. Giuliani Partners.
10. (past) Stances on Life/Immigration/Gun/Homosexual issues
11. Any moderate Republicans attracted to Giuliani's stances on social issues were turned off by Rudy's stances on torture and Guantanamo Bay.
12. Headaches, (not credible and unconfirmed) bomb threats and taking phone calls during speeches.
13. Did we mention that you have to play to stay?
(Updated) The very savvy Mark Halperin has his own take here.