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.

President Donald Trump selected a shiny red Tesla on the White House driveway as he showed support for Elon Musk's electric automaker.

The billionaire adviser to the president spoke at the beginning of the meeting with the heads of agencies such as the state department and Pentagon.