That was the moment, O'Rourke said, that everything changed for him.
“[The shooting] has changed me as a person,” O’Rourke, 46, told “Nightline.” “To have somebody come into this community and kill 22 people in an act of hatred and terror and violence, to know that that was inspired, at least in part, by the president. The killer using much of the same language the president uses.”
Watch the full story on "Nightline" TONIGHT at 12:35 a.m. ET on ABC.
After the shooting, O’Rourke, a former congressman who represented El Paso for six years, canceled his scheduled events and flew home.
While his fellow Democratic candidates were in Iowa, O’Rourke paused his campaign for a over a week to stay in El Paso, to mourn and help his community heal, but also to become a voice for the Texas border town and a foe of the president.
“El Paso made it all too clear to us the consequences of Donald Trump,” he said. “This hatred and this violence inspired by him, and the encouragement that he gives to those groups who traffic in lies, who traffic in racism and intolerance, causing someone to travel more than 600 miles--to bring that here to this community.”
O’Rourke has not held back his anger at President Trump. Audio of one tense exchange between O’Rourke and a reporter, in which O’Rourke asked the media to “connect the dots” and call out Trump for his rhetoric, went viral on Twitter.
“You know the s--- he’s been saying? He [Trump] has been calling Mexican immigrants rapists and criminals,” O’Rourke said to the reporter on Aug. 5, two days after the shooting. “He’s not tolerating violence, he’s inciting racism and violence in this country.”
O’Rourke has repeatedly, including in our interview, called Trump a white supremacist.
“[Trump] makes the case far better than I could. Right?” O’Rourke said. “If he calls Klansman and Nazis ‘very fine people.’ If at a rally in Florida this year when somebody says, ‘Shoot them,’ talking about immigrants, he laughs and smiles as the crowd roars their approval. When he sends 5,000 U.S. service members to communities like this one to line up against kids who are at their most desperate and vulnerable after having traveled 2,000 miles, and calls those kids animals, and then after calling them animals, puts them in cages.”
It’s no surprise that O’Rourke also is fiercely defensive of his hometown, which is largely Hispanic. El Paso, a site of detention centers for migrants attempting to cross the U.S.-Mexico border, has become a national flashpoint for the political crisis over treatment of detained migrants and their families.
“It’s a very loving, caring community. A very safe place,” O’Rourke told "Nightline" co-anchor Byron Pitts. “Definitely runs counter to the narrative that’s out there from the president and others that this is a dangerous place.”
“And unfortunately it’s not something new,” he continued. “Even before Trump, people have projected their fears or their anxieties or their racism or their intolerance on this community because it’s an 85% Mexican-American community. It’s literally connected to Ciudad Juarez, Mexico by land, by family, by history, by culture.”
During his time at home, O’Rourke crossed the border to Juarez to meet with Mexican officials and attend the funeral of Ivan Manzano, one of eight Mexican nationals killed in the El Paso shooting.
“I think that’s something very special, almost magical about El Paso. That’s probably part of what drew the killer here,” O’Rourke told “Nightline.” “I just feel like everyone by and large feels welcome and excited by who they are regardless of the differences.”
When he returned to the campaign trail on Aug. 15, O’Rourke presented himself as a changed candidate with a revamped campaign. He pledged to be more aggressive in confronting Trump and changed course to focus less on early primary states, like Iowa and New Hampshire, and instead focus on areas with large immigrant and minority populations.
He said he wanted to go to states that were traditionally visited less often on the trail to show that "everyone counts."
“When 22 people are killed in your community, when you're attending funeral after funeral, visiting them in their hospital rooms, seeing them try to come through the most grievous injuries, yeah, that pisses you off, and it makes it that much more urgent that we stop him [Trump], and that we bring the rest of the country into the conversation,” O’Rourke told “Nightline.”
It was also a push for O’Rourke to again find his footing in a presidential bid that has struggled to gain traction.
One of the voter criticisms against O’Rourke is his failed 2018 Senate run against Ted Cruz -- though the high-stakes race gave O’Rourke a fervent national following. Another is his lackluster performances at the first two democratic debates (ABC News hosts a third Democratic debate in mid-September).
“I want to do a better job. I really do,” O’Rourke told a group of voters at his home in El Paso last week. “I want to be strong. But … success is winning the nomination. Success is defeating Trump.”
O’Rourke, whose full name is Robert Francis O’Rourke, has had an unconventional path to becoming a presidential candidate.
His family has lived in El Paso for four generations. His father, Patrick O’Rourke, was also a politician and an El Paso County judge, an established member of the community who had high expectations for his son.
“Pat O'Rourke is known as a political force in El Paso. He was brash. He, you know, was not shy about speaking his mind. And he was popular,” said Chris Cummings, Beto O’Rourke’s childhood friend.
Beto and his friends, on the other hand, “were interested in skating, skateboarding,” Cummings said.
“Tony Hawk was pretty big at the time. We were into punk music. Some of us more than others, including Beto especially,” he added.
O’Rourke joined a hacking group called “The Cult of the Dead Cow,” regarded as the oldest surviving hacking group in the U.S., where he ran an online bulletin board under the handle “Psychedelic Warlord.”
“The Cult of the Dead Cow meant a lot to Beto O'Rourke,” said Joseph Menn, a Reuters investigative reporter and author of "Cult of the Dead Cow: How the Original Hacking Supergroup Might Just Save The World.” “In the first place, they were the cool kids, he told me. He wanted to be-- he wanted to be like them. He wanted to learn from them. They knew more about technology. They knew about music. And it was a way to belong to something and it was a way to learn.”
Menn said O’Rourke’s teenage years helped shape the future candidate.
“The most important thing for Beto was that he learned that there's real value in thinking like an outsider,” he said. “Hackers, again, are critical thinkers. They look from outside the system and they see flaws and they can point them out in a helpful way or they could use them for evil or crime or whatever.”
At 15, Beto O’Rourke went to boarding school in Virginia, after which he interned on Capitol Hill for former Rep. Ronald Coleman, D-Texas. Then, when O'Rourke graduated from Columbia University, he worked a series of odd jobs in New York: as an art mover, part-time nanny and at a small internet service provider.
He was also in a punk band called “Foss” and toured during college, but moved back to El Paso at age 25.
O’Rourke has openly talked about his two arrests -- one for burglary and one for a DUI.
He said the burglary charge, which was later dropped, was for sneaking under a fence with some friends and setting off an alarm at the University of Texas in El Paso. The more serious DUI charge, which O’Rourke called a “terrible mistake” during a 2018 interview with Ellen DeGeneres, was dismissed in 1999 after he completed a court-recommended DWI program.
Two years later, in 2001, his father was killed in a cycling accident.
“I think it did activate Beto a little bit,” Cummings said. “I think sometimes when you maybe lose a parent… it unleashes something that you're able to pursue that you couldn't while they were there… it can release your ambition. And I think maybe that's what happened with Beto.”
In 2005, O'Rourke was elected to the El Paso City Council. In 2012, he was elected to represent Texas' 16th Congressional District and served on the Armed Services and Veterans Affairs Committees. He gave up his House seat in 2018 to run for Senate.
Now, the prep schooler turned punk rocker turned politician is a married father of three aiming for the White House. He and his wife, Amy, have been married for 14 years.
Back on the campaign trail, pledging to show the country that El Paso is a community that will “not be defined by an act of terror or violence.”
“We've never been tested like we're being tested right now. The peril has never been greater,” O’Rourke said. “The match for that at a very divided moment is bringing people in and bringing people together. And what we saw in Texas, what I've always been a part of, is bringing everyone to this table and giving them a seat and involving them in the conversation.”