Marilea David, a lifelong Republican, is typical of the fan base, seeing in Palin an alternative to the old-boy network. “I think she is great. She is the only person I am excited about just now,” David said over coffee in west Des Moines…

Larry Sabato, director of the political centre at the University of Virginia, refuses to predict whether she will stand. “She does not know herself. She is just keeping the doors open. And she wants to keep all of us guessing. Sarah Palin being Sarah Palin will decide at the last minute, when she feels like it. She is not the sort to have a detailed masterplan, following it from day to day.”

Sabato predicts that if she runs, she will win Iowa. “More important is what happens if she is nominated. You are looking at a landslide to the Democrats. There is no one the Democrats want more. Obama would expect to win, even if the economy was bad. She is popular among Republicans but in the country as a whole she is unpopular.”