Mr. Musk is fundamentally a creature of Silicon Valley, a scene that initiated an entire revolution in power dressing. The young masters of that universe dressed down to show that they were members of a new elite — one that refused to dress like the grown-ups they were about to topple. It was the defeat of the suit by the T-shirt.

Donald Trump held an odd press event at the White House where several Tesla cars were lined up in front of the historic building. The president read from a pre-determined script when he announced he would buy a Tesla during the bizarre stunt to help boost the stocks of Elon Musk's business.