When Barack Obama’s sea of admirers look back on his always compelling and often brilliant Denver acceptance speech they will recall any number of new lines: his taunt that John McCain would follow bin Laden ”to the gates of hell,” but not to his cave; the allegation that if you lack fresh ideas then you use stale ones to scare the voters; or the observation that Mr McCain’s 90 per cent support record for George W Bush meant he was offering ”a 10 per cent chance on change”.

The following, highly mundane, line will probably not have lodged itself in their memories: ”So let me spell out exactly what that change would mean were I to be president.” Yet for the large minority of potential Democratic voters who were never swayed by Mr Obama’s loftiest oratory, it was the cue they had been waiting to hear.