David Letterman, in the opening monologue for his show just said:
"I understand that the French feel there still isn't enough evidence to invade Iraq, they still want more evidence. The LAST time France waited for more evidence, it rolled through downtown Paris !"
Which was met with wild cheering and applause from the audience, that even astonished Letterman himself. He finally reacted with a "Well alrighty, then... !"
American contempt for the French truly knows no bounds.
I think it largely stems from widespread perception of the French as arrogant, and a widespread knowledge of their contempt for us.