Sarah Palin winks at the camera, uses phrases such as “darn right” and “doggone it”, commands the small screen when thought to be at the brink of disaster and is, in short, a television phenomenon.

One week triumphant, another at bay, the Republican vice-presidential candidate has so far enthralled, appalled and intrigued much of America. She has yet to determine which image US voters and viewers will retain of her – that of the Reaganesque voice of small-town America or of a sub-George W. Bush figure barely able to make sense.