Only after Fox News announced that it had hired Sarah Palin as an "news analyst" did I realize that I’ve been subconsciously calling her Sarah Fox, Fox Palin, or Sarah Palin-Fox for a while now. She seems to be both the face that Fox wants to project and the audience it wants to capture: Palin represents the natural next stage in Fox’s evolution from talking heads who pretend to know things that aren’t true to those who sincerely believe things that aren’t true.

You could even reverse the order of that old illustration of evolution, that row of amphibian, monkey, and human figures walking increasingly upright out of the water, to show Fox’s development, starting with Shepard Smith, who really is some kind of journalist, to Bill O’Reilly, then gently moving down through Sean Hannity to Steve Doocy to Glenn Beck (an amphibian if ever there was one), and ending in Palin, who’s all fish.

That strikes me as a smooth progression, or at least it did until I watched her debut last night on O’Reilly. Her halting and deferential appearance–she even called Bill "the big man on campus"–may actually undercut her usefulness as a propaganda tool. She seemed nervous with Papa Bear, who was rather snappish. Opening with a video mash-up of TV personalities calling her an "ignorant rightwinger" who "doesn’t know anything"–meant to outrage her fans, but demeaning nonetheless–O’Reilly then weighed in with direct and often rapid-fire questions about "the perception…that you’re not that smart."

Like, what’s the graceful answer to that? O’Reilly had just shown John Heilemann, coauthor of Game Change, on 60 Minutes saying, "She still didn’t really understand why there was a North Korea and a South Korea, she was still regularly saying that Saddam Hussein had been behind 9/11, and literally the next day her son was about to ship off to Iraq and when they asked her who her son was going to fight, she couldn’t explain that." While Sarah flashed a fixed smile and told Bill that she didn’t let that sort of thing get to her, it started to dawn on me that, in one important respect, Fox and Palin are quite different: Sarah Fox is not nearly as clever as cable Fox.

O’Reilly seemed to be passive-aggressively telling her as much last night. Notably, he didn’t defend her by saying, "I know you and you’re one smart cookie!" Rather, he defended her with his usual invisible-hand-of-the-market argument, noting that both she and Fox are so successful, scoring such high ratings and raking in so much money, that so what if the pointy-heads deride them as wrong? Are those people topping The New York Times nonfiction bestseller list?

Bloomberg’s Margaret Carlson, on Monday night’s Countdown, said it best: "Sarah Palin is the latest in a line of populists, but she’s very different in one way. Populists historically have pretended not to know anything. They’ve actually been part of a fairly intellectual group of people. But she really doesn’t know anything. And it’s in God’s plan apparently that she not learn anything."

And that’s true: From Robert La Follette to Huey Long to George Wallace to, as Jon Stewart showed, the Oxford-educated Fox & Friends co-host Gretchen Carlson, most populists in American political history have only acted dumb, so as not to provoke the resentment of their audience. In fact, it’s been their pretense of being just folks that usually annoys their opponents the most, and occasionally leads to attacks intended to "expose" their hidden taste for opera or some other such tell-tale sign of being a smarty-pants.

That’s not going to happen to Palin. And anyway, real or faked, for Fox and the Republican Party dumbness in the name of demagoguery is no vice. Sarah Palin’s ability to sit there with a straight face and say things so stupid (like health care reform will lead to "death panels") that they break the sound barrier, leaving her opponents speechless, is a gift, not a failing. And as O’Reilly’s defense of Palin made clear, she doesn’t have to win a majority to succeed in her new job. As former McCain consultant and part-time Palin coach Mark McKinnon said, blabbing on Fox is "an easy job with very little accountability." It’s like being a spokesmodel for conservatism.

Nevertheless, given Palin’s history of "going rogue" by quitting pretty good gigs that turned onerous on her, she might still spontaneously combust in the cable channel’s face. She could back out of the contract as she has so many speaking engagements. She could have more Katie Couric moments on the air, in which her utter inability to recognize her own limitations makes her feel ambushed and paranoid. Her close mentors, like Fox’s Greta Van Susteren, could one day grow as frustrated with her as has Steve Schmidt, the top McCain consultant who helped choose her as the running mate and now trades accusations with her over who’s the bigger liar.

Even if you accept the viability of Fox’s intent–to rebuild the bridge between the big-money Wall Street elites of the GOP and its reactionary Christianist base–Palin’s performance last night ought to give you pause. Maybe she’s more mermaid than fish after all, a false siren for leaders who want to use her to control a base grown profoundly suspicious of the GOP establishment. When Glenn Beck asked her on Wednesday, in her second appearance as a Fox contributor, whether she would remain a Republican, she answered yes, if they get back to doing what they should do. To which Beck added, "A big if."

At that moment, you could almost see a long line of older Republican men who helped her rise in politics, beginning with former Alaska Governor Frank Murkowski and ending with John McCain, shaking their heads in shell-shocked disbelief.