A couple of weeks ago I wriggled my way into an overcrowded conference room at the World Economic Forum in Davos to listen to US vice-president Joe Biden talk about efforts to cure cancer with a “moonshot” (an American buzzword for high-risk, potentially high-return forms of research).

It was very revealing for two reasons. For one thing, when I saw Biden performing at close quarters, I finally realised why Democratic party elders have been muttering for months that he would be their preferred presidential candidate if Hillary Clinton fails to galvanise the voters.

Biden can connect with an audience with an ease that, sadly, Clinton often lacks: though he arrived woefully late for the moonshot meeting, he oozed such charm that the audience (almost) forgave him. And when he explained why he was involved in the moonshot initiative — namely because his own son died of brain cancer — he was compelling. “I have experienced the dreaded C word, which is the most frightening word that anyone wants to hear walking out of the office,” he said. “Had I run [for president] I would have liked to be the president who changes the face of cancer — we need an absolute moonshot.”