In a perfect world, we'd all evaluate candidates based on their health care plans and performance in The Social Policy Thunderdome, wherein a panel of leftwing bloggers would pepper politicians with substantial questions about weighty public issues, and those who proved incapable of the task would gracefully accept their inadequacy and drop out. Barring that, Matt's right to say that "things like appearances on Oprah's show are in some ways an improvement over the alternative...they're at least being swayed by the candidate's actual charisma or lack thereof (I, for instance, saw Hillary Clinton on Ellen last week and found her charming) whereas the main alternative isn't careful evaluation of the issues, but instead a seemingly arbitrary media filter wherein a prickly egomaniacal recovering alcoholic becomes the kind of guy you'd like to get a beer with."
That said, I'm still willing to help promote the Thunderdome concept.