On June 16, 2015, Donald Trump took the stage at his eponymous tower in New York City and announced his bid for the White House. His message was clear. “The U.S. has become a dumping ground for everyone else’s problems,” Trump said.

A day later, in South Carolina, 21-year-old Dylann Roof walked into Emanuel African Methodist Episcopal Church in Charleston, where members were holding Bible study. Using a .45-caliber Glock handgun and eight magazines of ammunition, Roof shot and killed nine people, including the pastor, the Rev. Clementa Pinckney, who was also a state senator. Before he arrived at the church, Roof posted a manifesto on his website, a racist tirade that expressed his motives. His message was also clear. “Integration has done nothing but bring Whites down to level of brute animals,” wrote Roof.

Indeed, when read together, Trump’s announcement and Roof’s manifesto offer a duet in racial grievance.

“When Mexico sends its people,” Trump said, “they’re not sending their best. They’re not sending you. They’re not sending you. They’re sending people that have lots of problems, and they’re bringing those problems with us. They’re bringing drugs. They’re bringing crime. They’re rapists. And some, I assume, are good people.”

“Hispanics are obviously a huge problem for Americans,” Roof wrote. “But there are good hispanics and bad hispanics.”

“It’s coming from more than Mexico,” Trump said. “It’s coming from all over South and Latin America, and it’s coming probably—probably—from the Middle East. But we don’t know. Because we have no protection and we have no competence, we don’t know what’s happening. And it’s got to stop and it’s got to stop fast.”

“The first website I came to was the Council of Conservative Citizens,” Roof wrote. “There were pages upon pages of these brutal black on White murders. I was in disbelief. … From this point I researched deeper and found out what was happening in Europe. I saw that the same things were happening in England and France, and in all the other Western European countries. Again I found myself in disbelief. “

Trump wanted to “make America great again,” where “America” was a metonym for a traditional, industrial, and white America, set against a rising tide of racial threats, from Hispanic immigrants and black protesters, to Muslim refugees and the specter of “radical Islamic terrorism.” With this promise to restore the moral, cultural, and political dominance of that white America, Trump grabbed the reins of the Republican Party and never let go. Roof, in his own telling, wanted to awaken white America to the alleged threat of blacks and other nonwhites. “We have no skinheads, no real KKK, no one doing anything but talking on the internet,” he wrote. “Well someone has to have the bravery to take it to the real world, and I guess that has to be me.” I alone can fix it.

Thursday, Roof was found guilty of hate crimes and other charges by a federal jury, and Donald Trump is president-elect of the United States. There’s no causal relationship between Trump and Roof, no tangible link between the two events. From a certain view, this means they’re unrelated. But that view is too narrow. Look at what radicalized Roof, at least in his own telling. Propaganda from white supremacist groups like the Council of Conservative Citizens; forums for white nationalists and anti-Semites; a narrative that told him he was oppressed, a “victim” of diversity in a nation overrun by “black crime.” At the church, say survivors, Roof exploded in grievance. “Y’all are raping our white women,” he reportedly said. “Y’all are taking over the world.”

These ideas were once marginal. But in the past year, they’ve been pulled into the mainstream by Trump and his presidential campaign. Trump has broadcast racial propaganda and anti-Semitic messages; his children have shared racist memes and reached out to white supremacist personalities. His campaign chairman Stephen Bannon, now chief strategist to Trump, pushed these narratives as CEO of Breitbart, a website where “black crime” gets a vertical and whose most famous writers lead online mobs of neo-Nazis and white supremacists. In the world of Bannon and Breitbart, white America is under siege by dark-skinned people and their white liberal enablers. Likewise, Roof’s manifesto reveals a belief system in which white America needs defenders from black criminals and other racialized threats. By his own account, Roof was radicalized by the killing of Trayvon Martin and the trial of George Zimmerman. He believed Martin attacked Zimmerman in an instance of “black-on-white crime.” Here’s what Breitbart published on Martin’s death and the trial: a “breaking news” story claiming Martin had drugs “in his system,” a witness account claiming that Martin had attacked Zimmerman “MMA-style,” and an op-ed denouncing President Obama as a “race-baiter” for sympathizing with Martin. In the past year, the website has alleged that outlets such as YouTube censor videos of “black-on-white” crime.

Roof’s worldview also fits comfortably with Breitbart-inflected rhetoric that represents “global special interests” as Jewish financial elites and treats all immigration as a dangerous imposition on the country. “She wants virtually unlimited immigration and refugee admissions, from the most dangerous regions of the world, to come into our country and to come into Minnesota, and you know it better than anybody,” Trump said, referring to Clinton in the final days of the campaign. “Her plan will import generations of terrorism, extremism, and radicalism into your schools and throughout your community. You already have it.”

Roof’s depiction of black Americans as violent and dangerous is just a few steps away from Trump’s depiction of black communities as violent and dangerous hellscapes that threaten the safety of the entire nation. “Poverty. Rejection. Horrible education. No housing. No homes. No ownership. Crime at levels nobody has seen,” said Trump, painting a dystopian picture of black life for a nearly all-white crowd of rallygoers in Ohio. “You can go to war zones in countries that we’re fighting and it’s safer than living in some of our inner cities.”

Trump did not cause Roof. But their temporal proximity reveals thematic connections between the two. Trump, the self-proclaimed billionaire, who blames immigrants and Muslims for America’s problems. Roof, the struggling young man, who blames black Americans (and others) for his stagnation. And if Trump embodies a white reaction to perceived decline in a changing world, then Roof represents that backlash in its most extreme and virulent form. Both Roof’s violence and Trump’s demagoguery flow from a shared swamp of resentment. The same white nationalists who led Roof down a path of hate and evil now gather in Washington, D.C., to celebrate the election of Trump as a triumph for their movement.

Roof’s crime is so monstrous that it may rankle to put him on the same continuum as Trump. But to see both with clear eyes is to see the link between demonization and aggression, between Trump’s rhetoric, simmering with menace, and the wave of harassment, intimidation, and outright violence that followed his victory. It’s to see both Donald Trump and Dylann Roof as heralds of the darkest forces in American life, to see their common heritage in a rising tide of white identity and white nationalism.

If Trump shares a heritage with Roof, then his victory is a painful asterisk on the outpouring of unity and hope that followed the Charleston shootings. “Clem understood that justice grows out of recognition of ourselves in each other, that my liberty depends on you being free, too,” said President Obama in his eulogy for the Rev. Pinckney, a remarkable meditation on racism, forgiveness, and Christian grace. “That history can’t be a sword to justify injustice, or a shield against progress, but must be a manual for how to avoid repeating the mistakes of the past—how to break the cycle. A roadway toward a better world.”

We honored the sacrifice of the dead, we asked God for guidance, and we took the Confederate flag down from its perch on South Carolina’s capitol, an expression—in Obama’s words—“of the amazing changes that have transformed this state and this country for the better, because of the work of so many people of goodwill, people of all races striving to form a more perfect union.”

Then, just 16 months and a few days later, we gave Donald Trump the White House. We didn’t avoid the mistakes of the past; we swerved in their path. We didn’t break the cycle; we strengthened it. Some of the same people who united around the Charleston Nine cast a ballot for the man who demanded murder for the Central Park Five. Seduced by demagoguery and the promise of new benefits and restored status, millions of Americans rejected the racial egalitarianism of Obama’s “more perfect union” in favor of a renewed color caste.

The painful truth is that Obama’s optimism was misplaced. Yes, Roof will face justice. But the ideas that radicalized him will thrive, not just as an amorphous force in American life, but as an active presence in American politics. They will thrive in the West Wing. They will thrive from the Oval Office. They will thrive in rebuke to Barack Obama himself, what he stands for, what he means.