Before the first presidential debate of 2004, President Bush told a rally that Kerry could just as soon debate himself for 90 minutes. As it turned out, it was Bush who debated himself -- and lost.
Kerry seemed fresh and relaxed, whereas Bush seemed flurried, agitated and piqued. Even assuming you had not seen or heard Kerry at all. Just listening to Bush alone, you would conclude this was some fledgling politician lost in boots too large for him.
Add to that Kerry's performance, at all times confident, composed, and steely. You didn't have to agree with him to feel that if Bush could be president, this guy surely could!
As one looked at Bush, one wondered if this was a man who had actually held the job for four years. He seemed to be having new epiphanies even during the course of the debate. In a moment reminiscent of Richard Nixon's "I am not a Crook", Bush declared, "I know Osama bin Laden attacked us. I know that".