Bryan Preston of Hot Air has a long, detailed post analyzing how Republicans lost the midterms:

What cost the GOP its majorities in Congress and statehouses? Nancy Pelosi and her wing of the Democrats are running around as though the elections validated their hard left view of the war and the world, but according to James Carville’s Democracy Corps, this election did no such thing.

What cost the GOP its power? Iraq? Foley? Look at page 6 of Democracy Corps’ post-election report. The GOP’s fortunes fatally cratered in the Fall of 2005, and were recovering ever since minus a couple of blips this year. What happened in the Fall of ‘05?

Katrina. That storm turned out to be the hurricane that changed history.

As Preston writes, "Combine 9-11 and Katrina, and the Bush administration has had to deal with two of the worst disasters in American history, one brought on by foreign aggression that was years in the making, and one the wrath of nature."

Near the start of the media's wretched Katrina coverage, which had painted the Superdome as the site of numerous rapes, and had fictitious snipers shooting at rescue helicopters, Mickey Kaus presciently noted that, "In short, Katrina gives [the media] a way to talk about Iraq without talking about Iraq." And they milked it for all that it was worth. Preston adds:

There’s a lesson in all of this, that’s an old one but an important one to remember: Demagoguery wins, and more so when it comes in the middle of a horrific disaster. Also, lies do indeed travel halfway around the world before the truth gets its boots on. By the time the story of New Orleans buses surfaced (only to be buried by the AP and ignored by the national media), the disaster had been framed as a Bush failure and the damage was already done. The media’s later mea culpa did nothing to change the basic narrative that already had a life of its own.

Which confirms something that Peggy Noonan wrote in August:

The other day ABC News's Internet political report, The Note, argued that President Bush, in his then-upcoming veto statement and other presentations, had better be at the top of his game if he wants his party to hold on to Congress in 2006. "[Mr. Bush] is going to need to be focused and impressive, not easy pickings for the Rich-Krugman-Dowd-Stewart axis."

As I read I nodded: That's exactly true. What was significant is that The Note did not designate as Mr. Bush's main and most effective foes Pelosi, Dodd, Reid, Biden, et al. Mr. Bush's mightiest competitors are columnists and a comedian with a fake-news show.

This is one reason the media is important. (Not "are important." Language evolves; usage changes; people vote with their tongues. It's not the correct "return to normality"; it's the incorrect "return to normalcy." It's not "the media are" it's "the media is." People see the media as one big thing.)

One big reason the media is important is that they change things. And they lead. On 9/11 itself it was the media--anchors, reporters, crews sent to the scene, analysts--that functioned, for roughly 10 hours, as the most visible leaders of the United States. The president was on a plane; the vice president was in the bunker and on the phone. It was on-air journalists who informed, created a seeming order, and reassured the public by their presence and personas and professionalism.

So they're important. But very recently it seems to me they're important because it is from the media that Mr. Bush's most effective opposition--attacks on his nature and leadership, attacks on his policies--comes. Among the Democrats an op-ed columnist has more impact than a minority leader.

It is common wisdom that newspapers are over. But when the most powerful voices against a powerful president at a crucial time are op-ed jockeys, newspapers are not over. Or perhaps one should say paper may be over, but news is not.

Rich Lowry has further election postmortems, here.

Update: Related thoughts on Republicans and the media, from a Hollywood (conservative) perspective.

Another Update: Dr. Helen explores the psychology of the big-screen TV:

My patients, regardless of political party, often come in and parrot to me the news they hear on tv without question. You know, the Dems are great, the Republicans evil and such. When I watched the news just now with Nancy Pelosi and Wolf Blitzer, it seemed that they were right in my media room, talking to me personally. TV encourages people to think by linking images in their brains. Are these images stronger and more persuasive on a big screen with high def like the new ones out than they were on the smaller less clear ones? Now that tvs are getting cheaper and cheaper as well as bigger and clearer, will the emotions of viewers become even easier to manipulate? And if so, how will that play out in a medium that is captured by the liberal media? As tv's get bigger, clearer, and cheaper, will we start to see blue everywhere?

That sounds like an environment tailor-made for a story like Katrina, which, while, as Kaus noted, was a way for the media to "to talk about Iraq without talking about Iraq", also had a similar fog-of-war type environment. It gave the media the opportunity to craft the most lurid stories possible, along with enormous amounts of plausible deniability afterwards.