The biggest names in America’s artificial-intelligence boom gathered at the San Francisco Opera House on election night for a show hosted by Nvidia Chief Executive Jensen Huang.They were there to see “The Marriage of Figaro.” But over wine and passed hors d’oeuvre, executives in tuxedos buzzed about an emerging threat to their industry, people in attendance said: Election results were coming in overwhelmingly against the massive build-out of computing capacity that Silicon Valley is counting on ...