Obama has a major TV booking most nights this week.

On Monday, he did Keith Olbermann’s popular MSNBC program, “Countdown.” On Wednesday, he’ll chat with David Letterman. For the second straight week, Obama is also a recurring face on Bill O’Reilly’s program. “The Factor” host keeps parceling out clips of their Republican National Convention interview.

Some Democrats criticized the Fox gambit, since it boosts O’Reilly and may do nothing for Obama, given that the audience is primarily made up of Republican senior citizens. As “O Force One” flew over Michigan on Monday, I raised that idea with Robert Gibbs, Obama’s communications strategist. He emphasized that, regardless of the media outlet, the goal is simply to get Obama’s message out during this critical phase of the campaign.

Jen Psaki, a traveling spokesperson for the senator, added that the media outreach complimented Obama’s political orientation. “This campaign has never been about speaking to just one wing of the party. We have visited parts of the country where Democrats have never been, and we are competing in parts of the country where Democrats have never competed,” she said. “Speaking to an audience that isn’t necessarily our base is par for the course — and part of the reason why Republicans and independents are taking a close look at Barack Obama,” Psaki added.

This outreach makes sense. Maybe Obama can pick off a few stray Republicans.

At a minimum, he might get more street cred with independents beyond O’Reilly’s base, if they think he proved his mettle under pressure. The hidden cost, however, is empowering O’Reilly to frame the debate.

I was reminded of that problem today during Obama’s press conference. The first question pressed Obama on his favorable remarks about the surge, from one of his feisty exchanges with O’Reilly. The real challenge, apparently, is winning over O’Reilly’s viewers without sounding like their hero.

Fox’s tight and symbiotic ties with the G.O.P. are well documented, but that does not rule out a Democratic detente, since it is still owned by Rupert Murdoch, a pragmatic mogul who has famously made peace with liberal politicians here and abroad.

Fox’s Republican role is out in force on Friday, however, as the RNC began an offensive against Obama based entirely on Bill O’Reilly’s framing from The Factor. A new RNC attack file contends Obama offered “conflicting threat assessments on Iran” based on “his interview with Bill O’Reilly.”

Some Democrats were also concerned about the Obama-O’Reilly exchange on Iraq. “Instead of presenting a clear definition of how he will realize the promise of change after eight failed years of George Bush, [Obama] blurred the distinction between himself and John McCain on Iraq,” lamented a former aide to Chris Dodd, who thrilled liberal Fox critics in a more combative exchange with O’Reilly during the Democratic primary last year.

“He gave up his greatest strength – opposition to the Iraq War – on O’Reilly’s show,” the operative continued. “If Obama’s lucky, he gained enough new Fox-watching supporters to make up for the Democrats he just alienated.”

The Obama campaign had no comment on the appearance or reaction from Democrats.

Robert Greenwald, the director of the documentary, “OutFoxed: Rupert Murdoch’s War on Journalism,” emailed a new video to supporters today. In it, he criticized Fox’s unbalanced treatment of Democratic politicians:

O’Reilly needled and interrupted Obama, trying to get him to simplify many of his answers — a far cry from the softballs O’Reilly lobbed at many prominent Republicans like Rudy Giuliani in the past.

In a separate interview with TWI, Greenwald said his new video shows how Fox News is using the same playbook this year that it effectively deployed against Sen. John Kerry’s presidential campaign in 2004.

“Those who don’t learn from history are forced to relive it,” Greenwald wrote in an email. “Here is proof positive of the Fox propaganda machine using the same language, the same tools the same attacks word for word against BO as they did against Kerry.” Raw Story, an alternative news site favored by the netroots, also criticized O’Reilly for a slanted, hectoring performance.

While most news channels focused on Sen. John McCain’s big night on Thursday, it was a battle of the B.O.s on Fox News.

Sen. Barack Obama, the Democratic presidential nominee, made a much-hyped appearance on “The O’Reilly Factor” to tangle with Bill O’Reilly. The talk-show host had been pushing so hard for an Obama visit, of course, his unrequited desire was a big topic at the secret meeting between Obama, NewsCorp head Rupert Murdoch and Fox News chief Roger Ailes.

Ever the showman, O’Reilly turned his new tape into a mini-series — only “Part 1″ aired Thursday (below) — and turned us commentators into previews for the remaining segments. But it was still good television.

Part 1 is about national security, with O’Reilly gingerly mugging as a salt-of-the-earth armchair general. He may pull down $9 million a year, but O’Reilly talks with the cadence and umbrage of any regular guy holding court at the bar — scrunching his face, interrupting, waving his hands and wondering whether Obama is tough enough to take on Iran.

He looked permanently perturbed with Obama’s answers. But he also offered his guest a few compliments. So Obama was correct to oppose the Iraq war as the “wrong battlefield,” O’Reilly observed, but wrong to oppose the surge. (Don’t even bother trying to square that.) Obama gave a good speech in Denver, O’Reilly conceded, but he still “bloviated” about Pakistan.

Obama was cool and cogent throughout, but O’Reilly’s audience presents demographic kryptonite to his political superpowers. Fox News viewers went for Bush by 9:1 last cycle, and prime-time shows — like The Factor — offer an even more conservative spin than daytime programming. Meanwhile, the average age of an O’Reilly viewer is 71. Obama has trouble with older Americans in general, but older Americans who voted for President George W. Bush and tune into O’Reilly? Even they may not be moved by this solid performance:

Fox News is promoting Obama's Thursday appearance.

As Sen. John McCain accepts the GOP presidential nomination on Thursday night, his opponent will enter the “No Spin Zone.”

Yes, Sen. Barack Obama is headed for Fox News, in a bid for Republican votes, by appearing for the first time ever on Bill O’Reilly’s prime-time show. While McCain aims his acceptance speech at voters beyond his base, Obama will be talking to the bright red Republicans who watch O’Reilly’s highly rated show. In the last presidential election, a whopping 88 percent of Fox viewers voted Republican, while only 7 percent voted Democratic.

Obama’s appearance also caps an unusually long and rocky exchange with O’Reilly.

A senior aide to Obama said the controversial anchor “shoved” him during a February altercation in New Hampshire, when O’Reilly tried to confront the Illinois senator to demand he appear on the Fox program. “I’ve worked two [presidential] campaigns, and I’ve never had a member of the press lay hands on a staff member before,” said the aide, Marvin Nicholson, who travels with Obama. Then, at a secret June meeting with Rupert Murdoch, the owner of Fox, and Roger Ailes, who runs it, Obama aired his concerns about the network’s biased coverage and agreed to appear on O’Reilly’s show, according to new reports from Vanity Fair and The Washington Post.

Beyond O’Reilly’s show, Fox News has been under siege this election season by several liberal groups supporting Obama. The channel was shut out of Democratic primary debates, after Democratic activists and bloggers scuttled its attempt to host debates with the Congressional Black Caucus. More recently, Fox was rocked by allegations of anti-Obama bias and racial prejudice in campaigns by Color of Change, a netroots group focused on black issues and civil rights — that was the battle featuring the rapper Nas on the Colbert Report — and a viral video campaign by Brave New Films.

Obama’s exclusive appearance, however, shows that he’s willing to tap the Fox News for potential conservative voters — even as his supporters try to marginalize its political role.