There is also money to be made: Wilson’s anti-Trump manifesto, “Everything Trump Touches Dies,” became an instant No. 1 New York Times best seller in 2018, and he is now a constant cable-TV presence. He has another book on the way, lucrative speaking gigs coming in and magazine assignments — though he says it has not offset the $4.5 million in income he estimates he has lost in recent years from would-be clients.

But despite this heightened media presence, waging what has become a shrinking insurgency can exact a psychic toll. “I’m not going to pretend that I’m not disappointed that we’ve had this attrition,” said Charlie Sykes, a conservative former radio host in Wisconsin whose umbrage over Trump has gained him cable ubiquity and a book of his own (“How the Right Lost Its Mind”). “It’s been this rolling, soul-crushing disappointment, watching people that you thought you knew.” But this, he added, had only strengthened his conviction. “It’s really not a hard choice,” he said. “There are advantages to being an only child.”

Never Trumpers are not so much a political movement as they are a slingshot army aimed at a single target. Finding someone to challenge Trump in a primary has been a persistent preoccupation. There have been varying degrees of hope. Jeff Flake, the Arizona senator, enjoyed a small boomlet in 2017 with his sustained critiques of Trump from the Senate and did not rule out running — until he did, and signed on as a commentator with CBS. John Kasich, the former Ohio governor whom Trump defeated in the 2016 primaries, has remained a kind of default possibility as someone who ran before, has continued to criticize Trump and appears to still irritate him, for whatever that’s worth.