SpaceX and Tesla — have submitted letters lobbying the U.S. trade representative on Trump administration tariff policies. The letters come as Musk oversees an effort to slash federal government spending and employee headcount at the behest of President Donald Trump.

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.