Washington Post reporter Michael Fletcher, today:

Think of the instant analysis after political debates about who “won.” Remember Al Gore's eye roll? What did that have to with the substance of his answers? But did it say somehting about his personality? Rightly or wrongly, these incidents often come to define presidents, and I don't think it is just because of the media coverage.

Given that polls taken immediately after Gore's debates with Bush found that viewers thought Gore won - and that much of the immediate post-debate media analysis suggested that he had won as well - it's pretty clear that the media's obsessive focus on his sighing and other nonsense is precisely the reason why those incidents came to define him. Viewers reacted positively to Gore.

It was only after the media endlessly beat him up for sighing and supposedly lying and other non-transgressions that the public saw him as an over-sighing, over-lying phony. If reporters want to claim that the media isn't responsible for the fact that silly things “come to define presidents,” they should probably come up with a better example than their treatment of Al Gore.