Kevin Drum has a lengthy (for a blog) analysis of the CNN exit polls. He believes terrorism was the deciding issue.
Compared to 2000, three times as many people thought world affairs was the most important issue in the election, and among those people, Bush gained 5 points of support. Multiply those two things together, and that’s a lot of extra votes for Bush.
Drum believes the “moral issues” were no more decisive than in 2000.