CLEVELAND — Avik Roy is a Republican’s Republican. A health care wonk and editor at Forbes, he has worked for three Republican presidential hopefuls — Mitt Romney, Rick Perry, and Marco Rubio. Much of his adult life has been dedicated to advancing the Republican Party and conservative ideals.

But when I caught up with Roy at a bar just outside the Republican convention, he said something I’ve never heard from an establishment conservative before: The Grand Old Party is going to die.

“I don’t think the Republican Party and the conservative movement are capable of reforming themselves in an incremental and gradual way,” he said. “There’s going to be a disruption.”

Roy isn’t happy about this: He believes it means the Democrats will dominate national American politics for some time. But he also believes the Republican Party has lost its right to govern, because it is driven by white nationalism rather than a true commitment to equality for all Americans.

“Until the conservative movement can stand up and live by that principle, it will not have the moral authority to lead the country,” he told me.

This is a standard assessment among liberals, but it is frankly shocking to hear from a prominent conservative thinker. Our conversation had the air of a confessional: of Roy admitting that he and his intellectual comrades had gone wrong, had failed, had sinned.

His history of conservatism was a Greek tragedy. It begins with a fatal error in 1964, survived on the willful self-delusion of people like Roy himself, and ended with Donald Trump.

“I think the conservative movement is fundamentally broken,” Roy tells me. “Trump is not a random act. This election is not a random act.”

The conservative movement’s founding error: Barry Goldwater

The conservative movement has something of a founding myth — Roy calls it an “origin story.”

In 1955, William F. Buckley created the intellectual architecture of modern conservatism by founding National Review, focusing on a free market, social conservatism, and a muscular foreign policy. Buckley’s ideals found purchase in the Republican Party in 1964, with the nomination of Barry Goldwater. While Goldwater lost the 1964 general election, his ideas eventually won out in the GOP, culminating in the Reagan Revolution of 1980.

Normally, Goldwater’s defeat is spun as a story of triumph: how the conservative movement eventually righted the ship of an unprincipled GOP. But according to Roy, it’s the first act of a tragedy.

“Goldwater’s nomination in 1964 was a historical disaster for the conservative movement,” Roy tells me, “because for the ensuing decades, it identified Democrats as the party of civil rights and Republicans as the party opposed to civil rights.”

“The gravitational center of the Republican Party is white nationalism”

Goldwater opposed the Civil Rights Act of 1964. He himself was not especially racist — he believed it was wrong, on free market grounds, for the federal government to force private businesses to desegregate. But this “principled” stance identified the GOP with the pro-segregation camp in everyone’s eyes, while the Democrats under Lyndon Johnson became the champions of anti-racism.

This had a double effect, Roy says. First, it forced black voters out of the GOP. Second, it invited in white racists who had previously been Democrats. Even though many Republicans voted for the Civil Rights Act in Congress, the post-Goldwater party became the party of aggrieved whites.

“The fact is, today, the Republican coalition has inherited the people who opposed the Civil Rights Act of 1964 — the Southern Democrats who are now Republicans,” Roy says. “Conservatives and Republicans have not come to terms with that problem.”

Conservative intellectuals were blind to the truth about the GOP — hence Trump

The available evidence compiled by historians and political scientists suggests that 1964 really was a pivotal political moment, in exactly the way Roy describes.

Yet Republican intellectuals have long denied this, fabricating a revisionist history in which Republicans were and always have been the party of civil rights. In 2012, National Review ran a lengthy cover story arguing that the standard history recounted by Roy was “popular but indefensible.”

This revisionism, according to Roy, points to a much bigger conservative delusion: They cannot admit that their party’s voters are motivated far more by white identity politics than by conservative ideals.

“Conservative intellectuals, and conservative politicians, have been in kind of a bubble,” Roy says. “We’ve had this view that the voters were with us on conservatism — philosophical, economic conservatism. In reality, the gravitational center of the Republican Party is white nationalism.”

Conservative intellectuals, for the most part, are horrified by racism. When they talk about believing in individual rights and equality, they really mean it. Because the Republican Party is the vehicle through which their ideas can be implemented, they need to believe that the party isn’t racist.

So they deny the party’s racist history, that its post-1964 success was a direct result of attracting whites disillusioned by the Democrats’ embrace of civil rights. And they deny that to this day, Republican voters are driven more by white resentment than by a principled commitment to the free market and individual liberty.

“It’s the power of wishful thinking. None of us want to accept that opposition to civil rights is the legacy that we’ve inherited,” Roy says.

He expands on this idea: “It’s a common observation on the left, but it’s an observation that a lot of us on the right genuinely believed wasn’t true — which is that conservatism has become, and has been for some time, much more about white identity politics than it has been about conservative political philosophy. I think today, even now, a lot of conservatives have not come to terms with that problem.”

This, Roy believes, is where the conservative intellectual class went astray. By refusing to admit the truth about their own party, they were powerless to stop the forces that led to Donald Trump’s rise. They told themselves, over and over again, that Goldwater’s victory was a triumph.

But in reality, it created the conditions under which Trump could thrive. Trump’s politics of aggrieved white nationalism — labeling black people criminals, Latinos rapists, and Muslims terrorists — succeeded because the party’s voting base was made up of the people who once opposed civil rights.

“[Trump] tapped into something that was latent in the Republican Party and conservative movement — but a lot of people in the conservative movement didn’t notice,” Roy concludes, glumly.

For conservatism to live, the conservative movement has to die

Over beers, I ask Roy how he feels about all of this personally. His answer is very sad.

“When Marco [Rubio] lost, I went through the five stages of grief. It was tough. I had to spend some time thinking about what to do for the next several years of my life,” he says.

“I left a comforting and rewarding career as a biotech investor to do this kind of work. I did it because I felt it was important, and I care about the country. Maybe it’s cheesy to say that, but I really sincerely do,” he continues. “So then, okay, what do I do? Do I do the same things I’ve been doing for the last four years? To me, just to do that to collect a paycheck didn’t make a lot of sense.”

This soul-searching led Roy to an uncomfortable conclusion: The Republican Party, and the conservative movement that propped it up, is doomed.

Both are too wedded to the politics of white nationalism to change how they act, but that just isn’t a winning formula in a nation that’s increasingly black and brown. Either the Republican Party will eat itself or a new party will rise and overtake its voting share.

“Either the disruption will come from the Republican Party representing cranky old white people and a new right-of-center party emerging in its place, or a third party will emerge, à la the Republicans emerging from the Whigs in the [1850s],” Roy says.

The work of conservative intellectuals today, he argues, is to devise a new conservatism — a political vision that adheres to limited government principles but genuinely appeals to a more diverse America.

“I think it’s incredibly important to take stock,” he says, “and build a new conservative movement that is genuinely about individual liberty.”

I don’t know how this would work. I don’t think Roy knows either.

For the entire history of modern conservatism, its ideals have been wedded to and marred by white supremacism. That’s Roy’s own diagnosis, and I think it’s correct. As a result, we have literally no experience in America of a politically viable conservative movement unmoored from white supremacy.

I’ve read dozens of conservative intellectuals writing compellingly about non-racist conservative ideals. Writers like Andrew Sullivan, Ross Douthat, Reihan Salam, Michael Brendan Dougherty, and too many others to count have put forward visions of a conservative party quite different from the one we have.

But not one of these writers, smart as they are, has been able to explain what actual political constituency could bring about this pure conservatism in practice. The fact is that limited government conservatism is not especially appealing to nonwhite Americans, whereas liberalism and social democracy are. The only ones for whom conservatism is a natural fit are Roy’s “cranky old white people” — and they’re dying off.

Maybe Roy and company will be able to solve this problem. I hope they do. America needs a viable, intellectually serious right-of-center party.

Because we now know what the alternative looks like. It’s Donald Trump.

Watch: How the Republican Party went from Lincoln to Trump