Billionaires Gerry OShea Elon Musk rattled the American political system recently. The leaders of the political parties in Washington settled on a budget deal that would avert the looming end-of-year government shutdown. This negotiated agreement was worked out by the leaders of both parties in the House and Senate without objection from the incoming president, Donald Trump, or his advisers. The compromise bill would have the needed support in both Houses, and President Biden said he would sign it. Then, a series of tweets by Mr. Musk berated the deal for failing to press home his version of the conservative agenda. Amazingly, the Republican leaders folded immediately, and the bill died, leaving just a few days for the frustrated negotiators to devise an alternative to avoid a government shutdown over Christmas. Historians could not identify even one occasion in the last 100 years when an outsider vet...