A few thoughts:
--I think John Judis is right about the overall effect of the speech, and the "single America" theme was striking enough (and repeated enough) to hit home. At the same time, Obama managed to personalize his economic message more effectively than ever before.
--As Frank points out, the sheer size of tonight's celebration was so noteworthy and effectively conveyed that it is hard to imagine Obama will not gain in the polls
--Jon Cohn writes, "Make no mistake, the agenda Obama laid out tonight is bolder than anything Democrats have seriously proposed since the 1960s." Indeed. I was (not unpleasantly) surprised by the boldness of Obama's proposals and the degree to which his campaign--and Democrats more generally--feel that they are free to move sharply to the left on economic issues and the role of government. As the speech wore on, Obama talked more about personal responsibility, but his fundamental message on the necessary role of the state in providing for its citizens struck me as remarkably bold, and rhetorically distinct from the Clinton years...
--...Which leads me to a related point: I imagine this speech was frusturating for conservatives. All of Obama's moves to the center were symbolic, while the policies he actually outlined were decidedly liberal.
--I disagree with Kate about the stage and the crowd, because I thought the setting managed to appear both larger-than-life and somehow intimate, but I agree with her about Obama's "defensive and feisty" attitude. It is a mantra among liberal pundits that Obama just needs to get tougher and hit back harder, which may be true; it also might be the case that the democratic nominee sometimes went a little too far on that score tonight. And, indeed, the contrast between his calls for unity and his attacks on McCain were occasionally jarring. (Obama may also live to regret this line: "But what I will not do is suggest that the Senator takes his positions for political purposes." Really? Never?)
Still, all-in-all, this was a wonderfully successful and powerful speech (with plenty of good soundbites), and though I think Kate is right that it may have been too long for people who watched it straight through, taking up more air time was probably not a bad strategy. It should also be noted that Obama's delivery is so superb that those of us who hear him talk all the time tend to take his gifts for granted. By almost any standard, this was a remarkably well delivered speech, and a remarkably good night for Obama's party.
A few final thoughts:
--The MSNBC commentary afterwards went so far beyond self-parody that my co-watchers were half-convinced the whole thing was an SNL spoof. MSNBC continues to be less nasty and dishonest than Fox, of course, but I can never remember Fox anchors gushing so much about Geroge W. Bush.
--The most powerful moment for this viewer was midway through the speech when the camera cut away (once again) to Michelle Obama gazing up at her husband. She did not look in awe of the man at the podium, nor did she seem to be acting for the camera. Rather, she looked extraordinarily proud of her husband and life partner, and the expression on her face radiated all of the ups and downs of what must be an exhausting stage in their life together. Her face reminded me, more than anything else, of the look Ingrid Berman gives Paul Henreid in Casablanca after he demands that the band at Rick's play La Marseillaise. Tonight's moment only lasted a few seconds, but the evening was worthwhile for it alone.