A jaded commentator could argue that not much is happening in the US presidential election. A year ago, Hillary Clinton was the favourite to win the White House, and she still is. A year ago, the Republicans were divided and unpopular, and they still are. But everything else that was said with confidence about this race has turned out to be wrong.

On the Democratic side, Barack Obama has fought a remarkably effective campaign. Weak in the televised debates, he has almost made this a strength – an expression of disdain for old-fashioned soundbite politics. His ability to electrify an audience with a set-piece address, his message of unity, and signs of Clinton fatigue have kept the nomination and the presidency tantalisingly within reach.