I really don’t have much to add to the comments by Rich, Dan, and especially Yuval below; I thought Michelle Obama did a little bit better than Yuval but entirely agree that the president’s speech was the least compelling of the major addresses of this convention.
Biden’s speechwriters were smart, I thought, to spend a lot of time on two attacks on Romney in order to let them really hit home rather than to take ten quick shots at him. After the speech, though, I thought that he had left a large burden on Obama to make the case that a second term would go better than the first. Obama didn’t do that, though, or even really acknowledge (as Biden did not either) that the pace of the recovery has been unacceptably slow. Instead we got another stay-the-course speech.
Obama has a real shot at winning because Americans cut him slack for inheriting a mess, because people don’t fully trust the Republicans, and because the base presidential vote for the Democrats has been climbing for decades. If he wins, it won’t be because of this speech or its message.