The former congressman was a persistent presence on his hometown's streets and on news shows Sunday, trying to offer comfort to his community and to lay at least partial responsibility at the doors of the White House.
The moment is fraught for O'Rourke. If he handles it well, it could inject new vibrancy to his candidacy, but if he overreaches, he risks being criticized for trying to exploit the moment for political expedience.
"He needs a big issue and he needs his biography to really bloom," said Brandon Rottinghaus, a University of Houston political science professor. "This is an opportunity for him to do both." Appearing at a candidate forum in Nevada when word of the shooting at a Walmart broke, O'Rourke at first appeared somewhat shaken. But he then immediately suspended campaigning and flew home to visit hospitalized shooting victims and speak to reporters on a nearby street corner. He sometimes used his fluent Spanish to reach audiences in Mexico, just across the Rio Grande.
On display was the kind of media savvy that made O'Rourke a rising Democratic star while nearly upsetting Texas Sen. Ted Cruz last year, but also the empathic, personal touch that comes with knowing a place so well. That may prove especially valuable as the nation comes to terms with a second mass shooting in less than 24 hours after El Paso, this one in Dayton, Ohio.
"Beto O'Rourke is a product of our community. He understands our community," said Texas Democratic state Rep. Cesar Blanco, whose district office is located just blocks from the Walmart where the El Paso shooting occurred. "For any individuals who are running for any kind of office right now, you have to understand what's happening in America and happening to innocent people around the country."
O'Rourke has made his hometown the centerpiece of his campaign, arguing that growing up on the border gives him special expertise on immigration while underscoring the value of inclusivity across language and cultural barriers.
Unlike most of his opponents for the Democratic nomination, O'Rourke now has an outsider's perch. But that may prove beneficial if a deeply divided Congress ultimately fails to act, as it usually does after mass shootings.
Another high-profile Democratic White House hopeful without a political day job, former Vice President Joe Biden, can similarly demand change without having to shoulder the legislative baggage that can come with doing so. On Saturday, Biden said he tried to call O'Rourke after the El Paso shooting, illustrating the Texan's deep connection to it.
Police say the killings were carried out by a 21-year-old who posted an online screed saying they were a response to an "invasion" of Hispanics coming across the U.S. southern border. After visiting the hospital Saturday night, O'Rourke said the people he met were "asking us to do something about this."
"Yes, it's the gun laws. Yes, it's the universal background checks. Yes, we should stop selling weapons of war to our communities," he said. "But I think that we also have to confront this hatred that I have never seen in my lifetime, and we certainly have not seen in El Paso."
Appearing on CNN on Sunday, O'Rourke carried the message further, declaring President Donald Trump a white nationalist. "The things that he has said both as a candidate and then as the president of the United States, this cannot be open for debate," O'Rourke said. He struck a similar chord in other televised appearances, saying on CBS' "Face the Nation" that "President Trump has a lot to do with what happened in El Paso."
O'Rourke added to that point on ABC's "This Week: "Someone who describes Mexican immigrants as rapists and criminals, who has sought to ban (all) Muslims, all people of one religion from traveling to the United States or who calls Nazis and white supremacists very fine people — he doesn't just tolerate, he encourages the kind of open racism and the violence that necessarily follows, that we saw here in El Paso, Texas."
By contrast. Trump spent the first hours after the El Paso and Dayton shootings out of sight at his New Jersey golf course, offering support and condolences via Twitter, but also promoting a celebrity fight and attacking his political foes. Late Sunday afternoon as he returned to Washington, Trump declared to reporters, "Hate has no place in our country, and we're going to take care of it."
Sometimes being reserved in the wake of tragedy can be a smart move. High-profile political tests can be as fraught with peril as much as full of opportunity. But confronting Trump with the nation watching has worked for O'Rourke before.
After leaving Congress in January, O'Rourke admitted to being in a "funk" as he drove around the country, posting online essays that amounted to public soul searching but were mocked as self-centered. Then Trump scheduled a February rally in El Paso to promote walling off the entire U.S.-Mexico border, and O'Rourke suddenly seized the spotlight anew — starring in a nearby counter rally and arguing that his hometown stood for everything the president didn't: tolerance and unity.
That performance helped O'Rourke storm into the presidential race a month later — only to see his once-strong polling and fundraising fall sharply as many voters took an early look and decided that he was perhaps not worth the hype. Now, with El Paso back in the spotlight, a second look from some may be possible.
"He's the emotions-on-your-sleeve kind of candidate that is comfortable talking about how these policies affect him, his family and his community," Rottinghaus said. "And that's the kind of thing that connects with people."