Renowned LGBT historian Martin Duberman, who turns 88 this August, says he has no nostalgia for the early, pre-Stonewall days of the gay movement.

Growing up in what he now ironically refers to as “liberated Manhattan,” and entering young adulthood in the 1950s, he remembers the extreme risks of being gay in public.

“I lived through it,” Duberman tells The Daily Beast. “When we went out at night to cruise or whatever, we would carry in our wallets the names of the one or two lawyers in New York who could get us out of jail if we were entrapped by a plainclothes cop.”

And yet, if this venerated scholar and author has a message for the current mainstream of the LGBT movement, it’s this: They need to look backwards for inspiration—back to the radical gay politics of the early 1970s that were, in turn, a direct response to the suffocating mid-century oppression that queer people of his generation bore.

Duberman, a pioneering gay activist and one of the original founders of the National Gay and Lesbian Task Force, has written over two dozen books and several plays over the last five decades. He has been especially concerned with cataloging queer and radical history, from the abolitionist movement to the Stonewall riots to the AIDS crisis.

His new book Has the Gay Movement Failed? (University of California Press) makes the provocative but compelling case that the fight for same-sex marriage marked a costly detour away from the radical politics at the root of the LGBT rights movement.

In the book, Duberman remembers fondly the “boisterous, uncompromising, hell-raising” politics of the Gay Liberation Front, an activist group that was active after the Stonewall riots of 1969, and wonders where the LGBT rights movement lost its way.

“How is it that GLF’s radical agenda morphed, more than forty years later, into a movement that stresses above all else the importance of the right to marriage—and secondarily, to participation on equal terms in killing our country’s ‘enemies’?” Duberman asks, in one of several scathing passages.

He is referencing what are commonly seen as the two most significant achievements of the LGBT rights movement: the 2011 rollback of “Don’t Ask, Don’t Tell” and the 2015 Obergefell Supreme Court decision that legalized same-sex marriage nationwide.

By liberal—rather than radical—standards, these were enormous accomplishments. But as Duberman argues in his latest book, if you look back at what early gay activist groups like the GLF wanted, it wasn’t marriage and military service but rather a radical restructuring of society itself—an interrogation of “traditional gender roles, the nuclear family structure, and lifetime, pair-bonded monogamy.”

“At the beginning,” says Duberman, “we were headed in the right direction—despite all the nonsense and the hyperbole and the infighting.”

That utopian and radical moment, though, was short-lived: “I go way back in my sense of discontent with the mainstream of the LGBTQ movement,” Duberman tells The Daily Beast—and by “way back,” Duberman means to nearly the start.

In 1973, shortly after becoming a professor at Lehman College in The City University of New York, Duberman became one of the founding members of the National Gay and Lesbian Task Force—which has since been renamed to the National LGBTQ Task Force.

Duberman tells the Daily Beast that he has recently been “rereading a diary [he] kept at the time” of the Task Force founding and that he found an entry in which he effectively warned himself that “this may be one more liberal organization which accepts our basic institutions as just fine, and is only interested in gaining access to them.”

“So I’ve had those feelings for a very long time,” says Duberman, who came to gay activism after his involvement in the movement against the Vietnam War.

It wasn’t long before he felt relegated to the margins of the gay movement he helped found. As Duberman narrates it in his latest book, the GLF—along with more radical countercultural groups more generally—“had lost its momentum” by the mid-1970s as the country turned toward conservatism.

“It really is the story of American radical protest,” Duberman tells The Daily Beast. “It flares up with drama and passion, and with demands that are substantial, and then rapidly—within three to four years—the movement itself is taken over by moderates, and the American public eventually attaches itself to a moderate solution.”

The AIDS crisis of the 1980s—coupled with an uncaring Reagan administration—briefly re-unified and galvanized the gay movement but, in the devastating aftermath, “‘sexual liberation,’” as Duberman writes, no longer widely appealed as a rallying cry.” The movement became more cautious—and more moderate. Duberman, at the time, was the director of the Center for Lesbian and Gay Studies at CUNY, which he founded in 1991.

“It was in this climate,” Duberman writes,” that the marriage crusade surfaced and began to pick up steam.”

The organization that would become the Human Rights Campaign was born. Radicals like Sylvia Rivera, a pioneering transgender activist, were, as Duberman notes, consigned to history in favor of a new “politics [that] was bent on respectability.” The majority of LGBT funding got funneled into the marriage equality fight. Picket fences—not radical justice—became the primary goal.

Even now that same-sex marriage has been legal nationwide for three years, Duberman remains skeptical that national LGBT rights organizations are meaningfully pivoting to more radical causes like immigration rights, economic justice, and transgender issues—causes that received relatively little attention in the buildup to the Obergefell decision.

“I wonder if they are waking up,” he says, when asked if the LGBT movement is now realizing what was ignored in the push for marriage. “If you mean the mainstream national gay organizations, I don’t see many signs of awakening. I do see them profoundly on the local level.” (With the SCOTUS retirement of Justice Anthony Kennedy, of course, suddenly marriage equality itself seems precarious—a presumably right-wing Trump appointee could help torpedo it.)

Duberman points to small groups like the Atlanta-based Southerners on New Ground, the Audre Lorde Project in Brooklyn, and the Sylvia Rivera Law Project in New York as examples of organizations that are currently living up to the radical potential of the early LGBT movement. But these organizations are tiny, with almost microscopic budgets. SONG, for example, lists a staff of just 16 people.

Recently, Duberman himself was part of one such small radical group: Queers for Economic Justice, an anti-capitalist LGBT organization based in New York. As Autostraddle reported, QEJ worked for twelve years on issues like queer and transgender homelessness and LGBT poverty before ceasing operations in 2014.

“We had to close our doors a few years ago,” Duberman tells The Daily Beast, “because we couldn’t afford the crappy little office that we had, and the one staff member who we were employing at starvation wages—and I think that says a lot about where the movement is at, and where the majority of the gay population is at.”

Indeed, Duberman doesn’t believe that there was some secret backroom conspiracy to prioritize same-sex marriage above all else—he writes in his book that the issue “did not land on the top of the agenda as the result of a ‘plot’”—but rather because “the majority of gay Americans” put it first.

In a country where, as CNBC recently reported, 70 percent of people believe they are middle-class even though only 50 percent are actually middle-class, it makes a sad sort of sense, Duberman argues, that many LGBT people would prioritize an issue like marriage over say, employment discrimination or wage inequality.

“It isn’t an accident, I’m trying to say, that the Human Rights Campaign has a budget of 20 million dollars a year or higher,” Duberman tells The Daily Beast. “They do accurately represent what the gay majority wants. And the gay majority wants in . They’re liberals at best. They believe that our basic institutions are sound.”

In the current political atmosphere, Duberman finds himself at the sometimes lonely intersection of LGBT politics and radical leftism. He doesn’t feel a clear sense of belonging with what he calls the “straight left”—typified in his mind by a socialist magazine like Jacobin—because he believes they “aren’t aware of the extent to which they’re harboring a kind of silent homophobia of their own,” focusing on “economic issues,” without “deal[ing] with some of the cultural issues that radical gays are stressing,” like gender fluidity and transgender rights. [Disclosure: The author has written about transgender rights for Jacobin.]

“The radical left, which long ago GLF represented, really did challenge some of the basic cultural assumptions that we’ve all grown up with—and it seems to me that the current young straight left isn’t dealing with those issues,” Duberman maintains.

He fears that the radical left of today is repeating the same mistake that the “socialist 1930s left did when the counterculture came along in the 1960s,” namely that they “either ignored it or denounced it because it didn’t fit in with classic Marxism and class analysis.”

“I see something of the same thing happening today,” Duberman says, seemingly a little wearied by the cyclical nature of the radical history he has documented all his life.

Looking back over his many years of writing and advocacy, it would be easy for him to give in to pessimism. He tells The Daily Beast that, early in his life he tried to stop being gay through conversion therapy because the negative societal messaging around homosexuality in the 1940s and ’50s had been so strong.

“I was in therapy for years, trying to get cured, because I had internalized the idea that I had a ‘character disorder,’ which was one of the favorite phrases of the day,” he says. “And I did everything conceivable—even giving up a lover and giving up sex in order to win my stripes in the culture as a decent human being.”

Eventually, in 1972, he found the courage to pen a New York Times article called “Homosexual Literature,” ending the first paragraph with this bold declaration: “I write as one who has not only read the literature, but lived the life.”

He tells The Daily Beast that he was only able to come out as early as he did—at age 42—because his mother had given him “unconditional love.”

“In other words,” he says,” she gave me a kind of structure and backbone. She allowed me to think I’m alright, really, except I have this one horrible problem: I’m queer.”

But even so, Duberman is cognizant of the effects that his early life had on him: “To this day, [gay] people of my generation are considerably damaged. They won’t always admit it, but we are.” Duberman, for one, says that he has “had trouble traveling” during his adult life because routine became so important to [his] sense of stability.”

“That kind of thing operates at a largely unconscious level, so you’re not even aware of your own mechanisms,” he tells The Daily Beast. “It’s only later on in life that you realize, ‘God, my life was so constricted and frightened all the time.’”

Over his decades of teaching and writing, Duberman says, his political involvement in the LGBT movement has “been in waves.” He is encouraged by movements like Occupy Wall Street, Black Lives Matter, and the young leftist support for Bernie Sanders—but he is also all too aware of how quickly radical energy can burn itself out.

“I’ve been involved in it and I’ve retreated,” he says. “Discouragement sets in periodically, and you really do need to retreat.”

Still, Duberman says that his “temperament is basically optimistic.” It’s fitting that his latest book returns to the days after Stonewall because, in his heart, Duberman still carries that same radical spark. The LGBT movement may be failing to live up to its radical promise, but he believes that it is not altogether doomed.

“If you’re pessimistically inclined, you’ll find lots of grounds for being so,” he says. “But I like to think that, this time around, maybe more eyes will get opened and the radical groups, now small, will grow in size and influence.”

“But it’s only a hope,” he adds.