Of the various explanations that have been advanced in such quarters to explain Trump’s hostile takeover of the GOP, Roy’s may be the most explosive. Although he was originally drawn to the party for its emphasis on economic freedom and self-reliance, he now believes that a substantial portion of Republicans were never motivated by those ideas. Rather than a conservative party that happens to incorporate cultural grievances, today’s GOP is, in his view, a vehicle for the racial resentment, nationalism, and nostalgia of older white voters. The element of the party that he once dismissed as a fringe, in other words, now seems to form its core.

“Trump showed me that white identity politics was the dominant force driving the Republican grass roots,” Roy told me when we met a couple of days later at a coffeehouse and co-working space in Palo Alto. Young women with adventurously colored hair pecked away on laptops; youths of South and East Asian descent streamed by our table, sporting giant headphones. Roy, who has a round face and a serious manner, wore a long-sleeved dark-blue Izod polo, his tortoiseshell sunglasses hanging from the collar.

Over a mug of skim-milk cappuccino, Roy explained that, while many fellow partisans still see Trump as an anomaly, he now believes Trump is the “logical end point” of the GOP’s long history of racialized politics. “Barry Goldwater was wrong to oppose the Civil Rights Act in 1964,” Roy told me. While the Arizona senator personally supported racial equality, he opposed the landmark legislation on constitutional grounds. His selection as the GOP nominee that year set off a slow-motion realignment of the parties, as the Democrats—once the party of southern segregation—became the party of minority rights, while the Republicans became dominant in the South. For a time, attracting white voters was a winning national strategy for the GOP. But today, Roy believes, the party finds itself not just electorally deficient but morally compromised. “If we aren’t going to confront that history as conservatives and Republicans,” he said, “we don’t deserve minority votes.”

Since Roy began elaborating his critique—in interviews with outlets like Vox, in speeches, and in columns for Forbes, where he is the opinion editor—the reaction has been intense. Liberals have saluted him; Paul Krugman, Roy’s frequent antagonist in health-care debates, lauded his “moral courage.” “Krugman has never said anything nice about me before!,” Roy marveled. He posted Krugman’s praise on Facebook, with the comment “Hell has frozen over.”

On the right, Roy has encountered more resistance. Interviewing Roy on the conservative Ricochet Podcast, Peter Robinson, a Reagan speechwriter, accused him of naively adopting the left’s critique of the right, and using the GOP’s hateful fringe to tar its decent mainstream. “Now it is apparently the popular thing on our side to say [to the left], ‘… You’ve got us dead to rights, whoa, we’re awful people,’ ” Robinson lamented. His co-host, Rob Long, asked Roy, “Why can’t the Republican Party have a winking, nodding relationship to its crackpot racial separatists, in the same way, let’s be frank, that the Democratic Party has with theirs—use their energy when we need to get out the vote in certain places and repudiate them when we’re forced to?”