When Evan Wolfson first saw reports that there had been “yet another shooting” this past weekend, he was about to board a flight back home from Australia, where he had spent the week trying to bring his ongoing campaign for marriage equality to that country. Watching the initial images out of Orlando he was “disgusted and horrified that once again we were going to go through this.” But it wasn’t until Wolfson spoke to his husband that he learned where the shooting had occurred: a gay nightclub.

“I started reading through the Twitter feed and all the different posts and got more and more heartsick at how awful this was,” Wolfson, widely seen as the primary architect of the marriage equality movement, recalled during an interview with The Daily Beast just two days later. “And of course once they began telling the stories and showing the pictures of the victims — so many of them were so young and so hopeful, and they were gay and non-gay people together, just all these beautiful people who had been killed. It is just heartbreaking, and infuriating.”

This was supposed to be a celebratory time for Wolfson. A week from Saturday, the new documentary The Freedom to Marry will have its world premiere at the Castro Theater in San Francisco as part of the Frameline LGBTQ Film Festival. The film’s title shares its name with the national organization Wolfson founded more than a decade ago. In the story about last year’s Supreme Court victory for the marriage equality movement, Wolfson emerges as both its hero and its heart.

As Wolfson recounts, filmmaker Eddie Rosenstein called “out of the blue” one day and asked if he remembered him. It turns out his parents were old friends of Wolfson’s family but the two men had not encountered each other since childhood. “This was as we were really in the home stretch of what had obviously been a very, very long campaign,” Wolfson says, adding that Rosenstein wanted to capture the “ascent to the summit” of marriage equality and “use that last chapter” to look back and tell the story of how they got to this point.

Despite the fact that viewers of the film will know how it ends, there is a still a palpable feeling of suspense that takes hold as the final Supreme Court decision approaches. But for Wolfson “the real drama is not so much how we finished the job at the end, but rather how we got to the point where we had transformed the hearts and minds of the country.”

“The powerful story, the epic transformation, is how we won in the court of public opinion in order to then be able to win in the court of law,” Wolfson continues. “We felt the momentum, we believed we had gotten there, we saw that our strategy was working and it was clear that we had extraordinary momentum, but you never know for sure. So we were really committed to not taking anything for granted.”

Throughout the documentary, various voices in the movement, including attorney and activist Mary Bonauto, who successfully argued the Obergefell v. Hodges case, express fear over the implications of a Supreme Court loss and how far it could set back the movement. Yet Wolfson never let himself embrace those doubts.

“I always really did believe we were going to win, and I don’t just mean in the last few months, I mean in the 32 years of working for this,” he says. “So I really believed going into this last stretch that if we had not won in June of 2015, we would have had to just pull ourselves together and keep working the same strategy to keep building that critical mass of states and get back in front of the Supreme Court.”

At the very end of the film, we see Wolfson sit down behind his desk to read through Justice Anthony Kennedy’s decision and begin to cry. “I realized two days later that the reason I was crying was just profound relief that even though I believed we would win, even though I always said we could keep going and would keep going, it was wonderful not to have to,” he says.

In his speech following the momentous milestone, President Obama said, “Progress on this journey often comes in small increments, sometimes two steps forward, one step back, propelled by the persistent effort of dedicated citizens. And then sometimes, there are days like this when that slow, steady effort is rewarded with justice that arrives like a thunderbolt.” The killing of 49 people at a gay nightclub in Orlando, Florida this week was the one of most devastating steps back the LGBT community has ever experienced.

Rather than merely be “heartsick and throw up our hands in a feeling of helplessness, which is what the NRA would like us to have,” Wolfson stresses that the LGBT community must “really use this moment to push for some meaningful action to limit the horrible epidemic of guns that is causing so many Americans to lose their lives.”

With that in mind, Wolfson has been attempting to share the lessons he learned in the fight for marriage with “all kinds of movements,” including the movement to prevent gun violence. Just as he built a critical mass of support for marriage equality state by state, “they are also working in multiple states in order to create the building blocks that will help turn the corner in what has so far been a dysfunctional Congress,” he says. “And to create the climate, not just in the general public, but amongst experts and academics, in order to undo the damaging misinterpretation of the Second Amendment that prevailed narrowly in the Supreme Court a few years ago.”

Meanwhile, Wolfson mostly dismisses the debate that aims to label the attack as either “terrorism” or a “hate crime,” emphasizing that the two are not mutually exclusive and even calling attention to reports that the killer himself may have been a closeted gay man. “We don’t know fully what was going on within him.” he says. “But what we do know, is that whatever motivated this killer, he wouldn’t have been able to kill this many people had he been unable to access the weaponry. That we know.”

And he is not prepared to give historically anti-gay public officials, such as Florida’s Governor Rick Scott and Attorney General Pam Bondi, a pass on their post-shooting hypocrisy when it comes to the LGBT community.

“The only real way to take that step forward it to connect the dots between anti-gay policy, anti-gay positions, anti-gay rhetoric that creates a climate that then invites anti-gay actions, including by some, who, like this shooter, may have their own internal wrestling with those anti-gay messages from society,” Wolfson says. “Obviously, it’s good to condemn anti-gay violence, but if you are also engaging in anti-gay rhetoric, anti-gay policy and anti-gay actions, you are contributing to a climate where some people are going to commit anti-gay violence.”

Still, just as he did throughout his decades-long fight for marriage equality, Wolfson sees hope on the horizon after Orlando, praising the “beauty and eloquence” of the survivors and allies who have spoken out against homophobia. “I’ve been so proud of our movement and our community,” Wolfson says. “And also of how so many people have come to better understand who gay people are and move to our side, in a way that wouldn’t have been true five years ago, 10 years ago, 20 years ago.”

To highlight this contrast, Wolfson recalls the 1973 arson attack that left 32 people dead at a gay bar in New Orleans. “Obviously people condemned the violence,” he says of the most comparable incident in American history to what we’ve seen this week, “but there was great disdain and very little support for gay people who had been killed.”

While he says we have seen some of that this time around, “we have also seen a huge embrace of the lesbian, gay, bisexual and transgender community and the massive wrong that has been done here.”

Updated 11:30 a.m., Thurs., June 16: A previous version of this article identified the filmaker as Andy Rosenstein, and since corrected to Eddie Rosenstein. We regret the error.