When I was in high school, I got a lot of attention from a group of older boys. They were swaggering cool kids, surfer types in a time — the early 1990s — and a place — San Diego — where that was the bleeding edge of cool. They were all white kids, tanned from long days at the beach with hair down to the middle of their backs. They were good looking, muscular and notorious, which at that particular time and at that particular school was just as good as popular.

They were also open white supremacists, talking about Tom Metzger and David Duke with the same muted fanaticism as they would earnestly discuss particularly good surf spots or strains of weed.

They also seemed to really like me. I could not figure that part out. I was not popular or notorious. I was awkward and pretentious. I had no money, threw no parties and I was weird-looking, not like anyone else around — my strong features and dark eyes fit in far better in many of the European countries I had lived in or visited with my peripatetic family over the years than in San Diego then. It was as puzzling as it was flattering to be sought out by the “cool” kids.

I would ask these schoolmates why they sought me out. By then, I had heard their white supremacist philosophies, which they treated alternately as an identity and as such a joke that I found them impossible to take seriously. “You’re one of the good ones,” they would tell me.

I didn’t understand the implacable forces of history then, nor the power of ironic nihilism. Back then, the Holocaust was ancient history to me, a distant memory recounted by friends of the family or relatives I barely knew, who had strange accents and faded tattoos with bizarre and horrible backstories. It was not for many years that I finally understood.

Hideous racist violence never occurs in a vacuum. The domestic terrorist who authorities say killed one person and injured three others at a synagogue on the last day of Passover in Poway, Calif., did so less than 10 miles from my old high school. He may have acted by himself, but as history and his Internet trail show, he was in no way a lone wolf. To cast him that way perpetuates a misleading narrative of individual rather than shared responsibility. And that is not just ahistoric, but it also keeps Americans from taking any meaningful steps to combat the rise of white supremacist violence.

The entire United States has yet to come to terms with the national legacy of centuries of genocides and human trafficking, but San Diego, in particular, drifts along obliviously. The city where I grew up has hardly begun to acknowledge its own role in enabling and perpetuating a mind-set that can so effortlessly become racialized violence — especially when hate crimes are treated like a game, the perpetrators egged on by gleeful, ghoulish cheerleaders watching on Facebook Live and keeping virtual score on 8chan and Stormfront.

California, and Southern California in particular, has been held up as an example of successful diversity by some and hopeless liberal failures by others, but in reality the state has been and continues to be shaped by competing forces of demographic change and white supremacist reaction. Nowhere is this more distilled than at the very farthest edge of the country, San Diego, at the gateway to Latin America.

The Ku Klux Klan (more specifically, the Exalted Cyclops of San Diego No. 64) seems to have first appeared in San Diego in the 1920s as part of a resurgence across the country in reaction to an influx of immigrants and asylum seekers entering the United States after World War I. At that point, the Klan in Southern California functioned primarily as a way to keep Mexican and Mexican American workers terrorized out of any attempts at organizing or demanding better working conditions.

Later, the Klan’s rhetoric, normalized and slightly sanitized through popular media and newspaper coverage, informed the attitudes of many Americans toward the forced “repatriations” of the 1930s, when more than a million people of Mexican descent were sent to Mexico or simply dumped at the border. Later still, in the 1970s, offshoots of this chapter formed unauthorized patrols to round up undocumented immigrants in the direct predecessors of today’s border militias. They’re more than just historical echoes: The first “civilian border patrol” was a publicity stunt dreamed up in 1977 by Duke, then-KKK leader.

The Klan in Southern California also reacted to the growing number of African Americans moving to the region from the South, fleeing Jim Crow laws and widespread informal discrimination during the Second Great Migration. The group began to join up with others with similar aims, such as the Silver Shirts League. Farm associations and fishing companies contracted with these organizations to keep laborers from unionizing or conducting any other “communist” activities, and redlining reached new heights around San Diego, with real estate agents forming “gentlemen’s agreements,” sealed with a wink and a smile that kept anyone who wasn’t white out of certain neighborhoods and concentrated in others.

The targets were Jewish residents as well as black ones. A huge, famous and occasionally controversial cross on La Jolla’s Mount Soledad is a relic of that time, a visible reminder that Jewish families were not welcome in that community. The University of California at San Diego’s Roger Revelle deserves credit for sparking major change; he threatened to take his visionary university system elsewhere until San Diego could figure itself out. “San Diego was a medium-sized, stodgy city, about as far from being an intellectual center as one could get,” Revelle wrote later. “Social and political dissent were frowned on; La Jolla even had a real estate broker’s covenant not to sell or rent houses to Jews.”

Revelle won the battle, but white supremacy never left. It did occasionally rebrand: Fallbrook, Calif., television repairman Tom Metzger, who in the 1970s led unauthorized border patrols with Duke, created the White Aryan Resistance (WAR) to further that aim in the 1980s. A few years later, I would walk past graffiti representing that very group on my way to school.

Today, California has more than 80 known hate groups, more than any other state, according to the Southern Poverty Law Center’s “Hate Map.” At least eight of these are active in San Diego, mostly white nationalist or anti-immigrant — including many that have grown dramatically amid the racially charged comments and corrosive disinformation that is a hallmark of the Trump administration.

Those of us who watch these groups have seen this all happen before. In San Diego in 2010, agitators gathered at Golden Hall to hurl anti-Semitic invective at then-Rep. Bob Filner (D). I tracked some of those responsible to the board Stormfront, where people who had attended the event promised to return with guns.

The lasting damage of all those years of hatred is not just in the past. It was in one of those previously redlined neighborhoods that my jocular, racist teenage schoolmates were popular rather than ostracized, that my own features were unusual enough to be remarkable, that yet another huge white cross sits atop a hill to oversee all those who live beneath it and remind everyone their place. (Once I realized that my neo-Nazi classmates’ “ironic” racism was, in fact, serious, I disavowed them; many of them have now been dead for a long time.) It is in the shadows of all of these events that Saturday’s synagogue shooting took place. I know all this because that is the neighborhood I lived in.

These attacks on houses of worship and mass shootings targeting “the other” are not products of lone wolves. They never were. They are the final, horrible results of the hidden histories that are knitted intimately and invisibly into all of our lives.