The congressman nearly sprang from his leather couch. “Oh, man,” he said. “You’ve got to go to Segundo Barrio.”

There was excitement in his voice, but also defiance. The barrio dead-ends at the border to Juarez, which for decades has been regarded as a murderous haven of traficantes violent (though recently its streets have become noticeably safer). Despite this, its neighbor El Paso has been ranked, based on violent crime statistics, as the safest city in America for the past four years. “I think that’s because of the fact that 26 percent of the residents are recent immigrants,” Mr. O’Rourke said. “These folks are strivers, focused on getting ahead. There’s self-policing. And because we’re on the border, we also have one of the highest concentrations of federal law enforcement in America.”

I met up with Mr. O’Rourke in Segundo Barrio and we took another spin. The streets were filling up with day visitors from Juarez gathering cheap products to take back across the pedestrian bridge. He drove me past some of his favorite sights in the neighborhood he calls “Texas’s Ellis Island, the launching pad to citizenship.”

A small bronze plaque on dusty South Oregon Street commemorated the spot where the famed novel of the 1910 Mexican Revolution, “Los de Abajo” (“Those From Below”) was written by Mariano Azuela. No such sign existed to memorialize the escape path taken into Mexico by Steve McQueen and Ali MacGraw in Sam Peckinpah’s 1972 film “The Getaway,” but Mr. O’Rourke gestured vaguely that it was in this vicinity.

A few blocks south resided Mr. O’Rourke’s favorite outlet for chicharrones (cracklings), while on Alameda he pointed an enthusiastic finger at Ciro’s (“awesome flautas with fresh guacamole”), though when the time came for a quick bite we opted for pumpkin empanadas at Bowie Bakery, a favorite pit stop of George W. Bush.

That evening we would see a more sophisticated side of El Paso: opening night to Gaspar Enriquez’s electrifying “Metaphors of El Barrio” temporary exhibition at the El Paso Museum of Art; grilled steaks with roasted chile peppers at the tony Café Central; and a tequila nightcap high up on Rim Road, at the home of one of the congressman’s constituents, the daughter of the former El Paso mayor Jonathan Rogers, who legendarily disdained formality to the point that he would cut off the neckties of visitors with his scissors.

From just beyond her front lawn we could look out onto the twinkling infinity of Juarez, Mexico, at night, and illuminated beneath it, “La Equis,” its hulking new X-shaped monument — a spot worth marking, no doubt, but by now the evidence was clear that the place to be was right where we stood.