After Musk announced the formation of the "America Party" on Saturday, Trump posted on his Truth Social platform that Musk had gone "off the rails."

Before we assess the eternally unrealized dream of a potent third party in American politics, let’s consider the specific, recently emergent dream of one specific man: Elon Musk.

Instead of the quadrennial dream of No Labels, in which high-minded donors put up the money for an imaginary white knight who never materializes, we may get the “America Party,” in which the world’s ...