I hate to be such a grouch about Kerry. He's done a lot of good work as a senator. He's had moments of tremendous bravery in the political arena as well as in war. He's often accused of duplicity when he's really just trying to be honest and thoughtful about the nuances of a difficult issue. But the guy just doesn't connect. If you want to sell him, you can't let him do the talking. You have to do it for him.
That's what this ad does. It reviews his career: his heroism in Vietnam, his expertise in national security and foreign affairs, his knowledge of tax and health care policy. It's a strong list. But people don't vote for a list. An ad is a chance to show them the candidate. In this case, they see the candidate in snippets but can't hear him. As you note, most of what they see is a senator gesturing in hearings. You could imagine similar footage of Edwards addressing a jury. He's doing something, but it's just a guy in a suit, talking.
What baffles me is the opening shot of Bush in military gear. I agree that the "Mission Accomplished" banner is now instantly embarrassing to the White House. But I don't think the same is true of Bush in the flight suit. The Dukakis tank ad worked because Dukakis looked ridiculous in the outfit immediately, and the ridiculous footage went on and on while the ad recounted all the military programs Dukakis had opposed. In this ad, Bush appears in the flight suit only briefly at the beginning, and he looks pretty swashbuckling, if you ask me. I'm tempted to conclude that Kerry's team chose this footage not to make Bush look ridiculous but to make him look too tough for Dean.
Kerry's five seconds at the end are painful to behold. His head sways from side to side as he lumbers toward the camera. His eyes are glazed. What he's looking at or thinking, I have no idea. The background—a corner of what appears to be a windowless, brick-walled room—leaves the impression that Kerry is trapped in some underground bunker where a squad of political consultants is forcing him to retake his line again and again. His voice is oddly high and soft, suggesting that something bad is happening to him, but he doesn't quite understand what. I don't want to vote for this man. I want to rescue him.