When my book “Occult America,” a history of supernatural religions in the U.S., appeared in 2009, I was surprised to receive an admiring phone call from a conservative documentarian and financier. He professed deep interest in the book’s themes, and encouraged me in my next work, “One Simple Idea,” an exploration of positive-mind metaphysics in American life. His name was Stephen K. Bannon. Although the media have characterized Bannon as the Disraeli of the dark side following his rise to power in the Trump administration, I knew him, and still do, as a deeply read and erudite observer of the American religious scene, with a keen appetite for mystical thought. Ronald Reagan, a hero of his, was not dissimilar. As I’ve written in the Washington Post and elsewhere, Reagan, from the start of his political career in the 1950s up through the first term of his presidency, adopted phrasing and ideas from the writings of a Los Angeles-based occult scholar named Manly P. Hall (1901-1990), whose 1928 encyclopedia arcana “The Secret Teachings of All Ages” …