The speed of the new consensus is perhaps the most remarkable thing about it. All it took was a new movie on global warming, fresh doubts about Hillary, and a growing desire to expunge George W Bush from the national memory banks . . . and suddenly Al Gore is anointed by the chattering classes as the next Democratic nominee. Al Gore? Yep. The man who, after eight years of peace and prosperity as vice-president, couldn’t manage to persuade Americans to continue the Clinton legacy with a president who could keep his trousers on. The man who sighed and huffed...