In 1980, Ronald Reagan asked voters whether they felt better off than four years earlier. He went on to defeat Jimmy Carter a few weeks later. On Friday Barack Obama raised the same question: “Do you think that you are better off now than you were four years ago or eight years ago?” he asked voters in Florida. “And if you don’t . . . do you think you can afford another four years of the same failed economic policies that we’ve had under George W. Bush?”

With unemployment on Friday jumping by 51,000 to take this year’s job losses to almost half a million, Mr Obama is mining a potentially rich seam. But a number of Democrats, including advisers to the Obama campaign, are worried that the Democratic party’s overall electoral advantage this year has not yet translated into comfortable leads for Mr Obama. On Friday Gallup showed Mr Obama just one point ahead of John McCain – a significant tightening in the past two weeks.