Clark Lea laid an egg in the second half. Or maybe neither Lea nor Kelly did.
USC has the most offensive weapons of any team we face this year. Our weakness at linebacker was exposed. Our secondary was fine, but a good passer and All-American level receivers can throw jump balls that can't be defended.
I think the bottom line is that the defense just isn't that good. And yes, we have the offense to thank for a) scoring 30, b) only allowing USC to touch the ball 4 times in the second half.