The night of Tuesday, May 28, the documentary Running With Beto will premiere on HBO—and, in the eyes of the Beto 2020 camp, hopefully inject some energy into his presidential campaign.

Directed by David Modigliani, the film, which premiered at SXSW, provides a fly-on-the-wall look at then-Democratic congressman Beto O’Rourke’s recent run for Senate in his home state of Texas, where the upstart candidate, fueled by grassroots fundraising and viral speeches, almost defeated Republican incumbent Ted Cruz (no small feat in the historically red Lone Star State).

“David asked me if he could do this one day at breakfast in Austin,” Beto told a raucous crowd following its SXSW premiere. “I was like, what the fuck, I mean, we’re running for Senate and if you want to bring a camera along sometimes… I just didn’t think it would be this.”

In the doc, Beto comes off as charismatic yet controlling—its most revealing moments being ones where he is seen dressing down his clearly overworked staff for their perceived lack of preparedness. The person on the receiving end of most of the scoldings is Cynthia Cano, his road manager. At several tense points in the film, Cano is criticized by Beto—in front of her campaign colleagues—for not leaving enough time in his schedule for media interviews, having him be late to campaign events, and not adequately prepping him for those events. (Cano views Beto’s penchant for going long in his speeches and wanting to speak with every single constituent and/or person with a microphone as the reason for his constant tardiness and lack of prep time, which appears to be the more likely culprit.)

After Beto was narrowly defeated by Cruz, he delivered a concession speech in front of thousands of supporters in his backyard of El Paso, where he exclaimed, “I’m so fucking proud of you guys.” Just prior to that, in the backstage area of the venue, Modigliani’s cameras caught Beto and his top staffers (as well as his teary-eyed wife, Amy) in an intimate huddle, where the Senate candidate apologized to them for being “a giant asshole.”

“I just feel very, very lucky, and I love you guys more than you’ll ever know,” he says. “I know I was a giant asshole to be around sometimes, and you all never allowed my shortcomings to get in the way of running the best campaign this state has ever seen.” With that, the camera cuts to Cano, who gives a knowing look.

You can watch that scene here, exclusively at The Daily Beast: