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.

As the Tesla backlash grows, the president held an infomercial at the White House to shore up the fortunes of his biggest supporter. Earlier this week, Donald Trump staged what historians believe to be a presidential first: a stilted,

Tesla has joined the ranks of U.S. companies concerned that Trump's aggressive tariff policies may negatively affect global sales.