Given his undoubted charisma and his way with words, he has the potential to be a big vote winner for the Tories. But, and it is in important but, voters who regard humour and a cavalier style as an asset in a city mayor with few real powers might seek different qualities in a national leader. Last week, in an interview with the Sunday Times, he talked about how his six years as mayor had given him the administrative experience that would stand him in good stead in national politics. He has a point. But if he is to be a real vote-winner for his party on the national stage, he needs more. He needs to get serious.