The Cerebral, Bach-Loving Patrician Who Wrote Trump’s Playbook

In a memorable exchange during a Republican primary debate in January 2016, Senator Ted Cruz of Texas needled the upstart candidate Donald Trump, saying he was not a true conservative and adding, “Not a lot of conservatives come out of Manhattan.” Mr. Trump was ready with a retort. “Conservatives actually do come out of Manhattan,” he replied, “including William F. Buckley.” It was obvious why Mr. Trump would invoke William F. Buckley Jr. — the author, columnist, magazine editor, TV debater and political candidate who died at 82 in 2008 (and who did work for decades in Manhattan). Mr. Buckley...