Just before the ten minute mark in this video is the money shot:

"I wasn't born with a silver spoon in my mouth. Michelle wasn't, either," the president said to a crowd of 400 students at Lorain County Community College in Elyria, Ohio. “But somebody gave us a chance. Just like these folks up here are looking for a chance.”

That's a pretty damn direct assault on Mitt Romney, right there. There's a real risk in this discussion of class—as comment threads have taught us, Americans love to defend multimillionaires and corporations—but his phrasing of class issues feels pretty decent here. The question is whether this speech can survive hundreds of repetitions and minor variations over the next half-year, or whether it'll turn into something incautious. It's a very fine line the president has to walk.