On Saturday, a gunman opened fire at a supermarket in a predominantly Black neighborhood of Buffalo, New York, killing 10 people and injuring three others. Before the attack, the suspected shooter posted a 180-page document full of racist and antisemitic rhetoric.

Michael Curry, chair of the NAACP Advocacy and Policy Committee, joined Boston Public Radio to discuss white supremacy in the United States and the racism behind the attack, in which 11 of the 13 victims were Black.

“The rhetoric that was coming out of this young man's writing and his belief was really the hate that we've allowed to fester over the last several years — really, for this country's history — but [that] really came to a head under the last presidency,” he said. “We've allowed it to go unchecked.”

In his writing, the gunman cited the "Great Replacement,” a racist conspiracy theory that asserts non-white people are being brought to the U.S. in order to make white people a minority, according to the Anti-Defamation League. The conspiracy theory is often cited in white supremacist groups online, but it has also been mentioned by conservative television commentators and politicians in recent years.

Curry said he is not surprised that this ideology is growing among young white people like the suspected Buffalo shooter.

“He or she could be sitting thinking, ‘OK, I need to defend my country or my people for my race,’” Curry said. “If we don't check that, there will be many more incidents like this.”

The NAACP chair wants to see more accountability and action around white supremacist extremism.

“We've not approached it with the same sort of urgency that we need to,” he said. “I think maybe this Buffalo shooting could be a tipping point for us all that we need to weed it out. We need to find it. We need to deprogram people who are walking around with this replacement theory garbage and hopefully prevent the next mass shooting.”

Curry is chair of the NAACP Advocacy and Policy Committee, and is president and CEO of the Mass League of Community Health Centers.