That famous sign in the 1992 Clinton war room didn't just read "It's the economy, stupid," but also "Change versus more of the same" (plus "Don't forget health care").
Tonight, Biden's refrain is "That's not change, that's more of the same."
At the end of the day, the "change" theme probably remains Obama's single most potent weapon.
A minor quibble: Biden frequently paraphrases lines in his prepared text, often to less crisp effect. He should stick with the teleprompter.