But it has only been in this campaign cycle that we have seen the liberal echo chamber — from websites like The Huffington Post and cable commentators like Keith Olbermann — be able consistently to drive a campaign story line. In the past, it was only the conservative echo chamber — Matt Drudge, Rush Limbaugh — who regularly drove stories in new media and old media alike. This is a huge shift.

3. The blurring of lines between journalist and advocate. The Huffington Post is an admirable enterprise, staking a flag in a new media landscape. Its success this year was made possible by the openness of the Web and the decline in what was once the near-monopoly power of old media institutions like The New York Times to set the agenda on national politics. (Politico is itself an experiment in that new media landscape — one reason we admire Huffington.)

But it covers politics with a mix of traditional reporters and analysts, like Tom Edsall, and with people who define themselves principally as advocates. Many of these advocates, like The Huffington Post as a whole, are proudly cheering for Obama. (This is true even though the site, almost apologetically, broke the story about Obama’s recent remarks saying small-town Pennsylvanians turn to guns and God because they are bitter.)

Obama benefits also from probably the strongest bias of traditional, old media reporters: Against partisan combat and for a brand of politics that would transcend differences in favor of cooperation and centrism on elite issues like entitlement reform. Many of these reporters see Clinton representing bad, angry, contrived old politics and Obama bravely leading the way for good, civil, authentic new politics.

4. Covering politics as it is versus as it should be. Many of the people complaining about ABC’s coverage, even some Clinton supporters, disliked the questions and the tone because they felt they were serving as a warm-up act for Republican attacks in the fall.

It is not an easy balance. It is not reporters’ job to promote the opposition’s story lines — especially dubious ones like the suggestion that because Obama does not favor flag pins on his lapel it reflects adversely on his patriotism. But nor can serious reporters avert their gaze from the fact that questions about how well candidates connect personally and culturally with voters matter a lot — they were decisive factors in both the 2000 and 2004 elections.

Gibson and Stephanopoulos handled this balancing act responsibly. They asked tough questions of both candidates. In the wake of the debate, it is time for Obama’s cheerleaders in the media to ask some questions of themselves.