There are two issues here, trivialization and bias, but they're related.

Somewhere along the line, TV news stopped reporting on candidates' policies, and turned instead to trivia that supposedly reveal their personalities. We hear about Mr. Kerry's haircuts, not his health care proposals. We hear about George Bush's brush-cutting, not his environmental policies.

Even on its own terms, such reporting often gets it wrong, because journalists aren't especially good at judging character.