Over the past few days, a music video entitled Red, White and Milf has appeared all over the internet. It features a cowboy singing a novelty song about Sarah Palin, while three women resembling the Republican vice-presidential candidate dance in skimpy outfits in the background. Actually, dancing is the least of it. One runs her tongue along the barrel of a rifle, one whips another with a US flag, one dips her finger into a pie and feeds it to another, before smearing it over the woman’s face and licking it off. It’s a lot of suggestion.

For better or worse Palin is the highest-profile female politician in the world now, which makes the constant objectification of her particularly galling. This began within days of her nomination, of course, when doctored pictures of her showed up on the internet, head superimposed on to a rifle-toting model in a stars-and-stripes bikini. While Palin calls herself a feminist — “a sign of perverse progress”, sighs the pioneering US writer Robin Morgan — her views exist at a frightening distance from any recognisable women’s rights agenda.

In a disastrous interview on CBS, for instance, Palin was asked by the presenter Katie Couric: “If a 15-year-old is raped by her father, do you believe it should be illegal for her to get an abortion?” She answered: “I would counsel to choose life.”

But as the attacks on her have grown, they have become more disturbing. This is partly because — like many of the sexist attacks on Hillary Clinton during the primaries — they have come from people who would usually consider themselves progressive.

“Taken with the sexist attacks on Clinton, this underlines the fact that any woman entering public life runs the risk of being reduced to the most basic female stereotype that springs to mind — in Clinton’s case it was the ball breaker; in Palin’s case, the porn star.

Palin is learnt to have emails from women saying: “You know, I used to think about going into politics, but now I see stuff like this, and I think there’s no way.” Morgan says she’s “not

surprised, but I am astonished” that such attacks are still made on female politicians, and believes that it will only be when there are as many women as men in politics.”