Richie was clean-cut, wholesome, an absolute goody-goody, and everybody loved him. Fonzie, especially in the early series, was a tough nut. Greased-back hair, always astride his outlaw motorbike, decked out in Marlon Brando T-shirt, Fonzie inspired fear and envy in men, and swoons among the gals.

Everyone was frightened of Fonzie. He could banish bad guys with a look. In one episode, Fonzie tried to teach Richie his style. Richie practised the grimaces, the flexes, the stares, but alas the bad guys were not impressed and certainly not deterred.

In the midst of a desperate scrape, Richie turned to Fonzie imploringly and asked: Why are my deadly looks, threatening flexes and strategic grimaces having no effect?

Oh yeah, Fonzie replied, I forgot to tell you. For all that to work, once in your life you have to have hit someone. You cannot imagine a deeper strategic insight.

At some point, Obama is going to have to do something seriously unpleasant to someone.