But Williamson has more in common with President Trump than she — and indeed many voters — might admit, and it’s not just that both have used personal celebrity as a springboard into politics. At their core, both are also prime representatives of one of the most important and formative spiritual trends in American life: the notion that we can transform our material circumstances through faith in our personal willpower. Trump’s authoritarian cult of personality and Williamson’s woo-inflected belief in the power of “self-actualization” both come from the quintessentially American conviction that the quickest and surest route to Ultimate Reality can be found within ourselves.

Williamson’s connection with this tradition is more obvious. She came to prominence popularizing and commenting on a four-volume 1975 metaphysical tome called “A Course in Miracles,” by Helen Schucman, a research psychologist in Manhattan who believed herself to be transcribing the words of Jesus. “A Course in Miracles” tells readers that reality is an illusion and that by changing their perception of it, they can alter their circumstances and achieve astonishing things, personally and professionally. Several of Williamson’s books elaborate on those themes. In “The Law of Divine Compensation” in 2012, for example, Williamson conveyed to readers a supposedly surefire universal principle: “To whatever extent your mind is aligned with love, you will receive divine compensation for any lack in your material existence. From spiritual substance will come material manifestation. This is not just a theory; it is a fact.”

Trump, whose egotism often appears self-taught, or at least instinctual, was also influenced by a variant of this pseudo-theology, albeit one more palatable to East Coast business executives. He has spoken openly about his family’s long and close relationship with Norman Vincent Peale, a 20th-century writer well-known for his best-selling 1952 book, “The Power of Positive Thinking.” While Peale was formally a Christian — he was the pastor of Marble Collegiate Church in New York for more than 50 years — his writings were suffused with the idea that you can transmute and augment yourself through sheer mental exertion. “Formulate and stamp indelibly on your mind a mental picture of yourself as succeeding,” he wrote. “Never permit it to fade.” By thinking it, his readers would make it true.