From the moment the candidates walked out on to the stage in Atlanta, it was obvious that this debate was a big mistake for Joe Biden. By the end, it was a train wreck for his campaign.
The incumbent president, who desperately needed to show vitality, looked from the start like an old man. His gait was stiff and his voice tentative. His energy was markedly different from his triumphant State of the Union address just a few months ago.
