Remember Barack Obama? Time was, you couldn't turn on the television or open a newspaper without seeing our next president - for that was how we thought of him, in those days. But lately the man with the striped ties and the big ears has been more difficult to find in the American mediascape. On Sunday, Obama gave a wide-ranging interview to one of the morning talkshows, in which he offered a thoughtful, complex assessment of the Iraq surge and discussed how rising unemployment and the Fannie-Freddie bailout might change his economic plans. What crumb did the wire services seize upon? A throwaway line about basketball: "Obama offers Palin a game of hoops."

John McCain's running mate might be avoiding the press, but Sarah Palin is everywhere - on the covers of Time and Newsweek, not to mention People and Us Weekly. You'd be forgiven if you thought that the woman was running for president herself. A good fraction of the coverage has been harsh, yes. But it has also been frustratingly distracted. The idiotic rumours that her (now pregnant) daughter is the true mother of child No 5 were unworthy of a telenovela, but that didn't stop the New York Times from putting four different reporters on the case. Her string of alleged abuses of power, her rejection of the realities of climate change, her apparent ignorance of the basics of the mortgage market: these are stories worth covering, and they've got a bit of play. But they've been drowned out by the dumber stories about her hair or her family, and by the Republican chorus that the media have it in for her.

"Shame on you!" they shouted in unison, like Puritans around a ducking stool, as Palin scolded the media during her speech last Wednesday in St Paul. It's ironic, to say the least, that the GOP has decided to hit the press in order to win an election for McCain, a man who has enjoyed the media's adulation for 25 years and who used to call reporters "my base". But the stratagem is plain: discredit the messenger, and reports on Palin's serious ethics problems or shoddy record can be written off as baseless (and sexist) attacks by a group with a vendetta, hell-bent on destroying an unimpeachable hockey mom who shares your values. Unlike that other guy.

In its malign simplicity, the beat-the-press theme bears the mark of Steve Schmidt, the Karl Rove acolyte who has imposed an impressive unity on the once-errant McCain campaign. For him, reporters are on "a mission to destroy" their VP candidate, hopelessly infatuated with Obama and not to be trusted. But demonising the media and keeping the running mate under a form of house arrest are not winning tactics. Indeed, like the Palin pick itself, the media bashing does little more than excite the base.

For despite the hysteria of a few lefties who seem never to have heard of a convention bounce, Palin has not instantly won the hearts of millions of undecided voters in Pennsylvania, Ohio and Michigan. On the contrary, outside the base she hasn't played very well – and she has nowhere to go but down. The McCain campaign understands that inevitability. Palin's sequestration is testament to the fact that she cannot withstand the scrutiny that the press (though not, apparently, McCain's vetting process) demands. And the campaign's legal actions in Alaska, where it's doing its best to block any embarrassing new revelations surrounding her firing of her public safety commissioner, bespeak a real fear of an October surprise.

It's a war against information. The McCain team knows that if the media do their job and give Palin the same scrutiny that any candidate for high office must endure, she will collapse. Whether that will happen, or whether the press will be cowed by the GOP into doubting its own raison d'être, remains to be seen. Palin will emerge from her televisual purdah at the end of this week, when she'll face Charles Gibson, the ABC anchor who has not won much praise lately for hard-hitting journalism. The Clinton-Obama debate that he moderated (along with George Stephanopoulos) set new standards for vacuity, with nearly an hour devoted to such non-topics as the iconology of flag lapel pins. Rick Hertzberg, the indispensable analyst at the New Yorker, called it "something akin to a federal crime".

Here's hoping that Gibson asks Palin a few questions about her record - and also a few about instability in Pakistan or how to increase liquidity in credit markets. But don't get your hopes up. Bizarrely, Gibson will interview Palin over the course of a few days, meaning that if the questioning turns in a direction the campaign doesn't like, later sessions can be cancelled. If he fluffs it, we may have to wait all the way until the vice-presidential debate on October 8 to put real questions to the woman who might one day be president.