Ahead of the one-year anniversary of the Jan. 6 riots, ProPublica reporter and FRONTLINE correspondent A.C. Thompson joined Boston Public Radio to share what’s happened since the Capitol riots and updates to his documentary, “American Insurrection.”

“After Jan. 6, what you sort of see today is that these movements have not gone away, but they are still here. They're constantly sort of evolving and changing,” Thompson said. “But extremist ideas have absolutely migrated to the center of discourse in many places in this country. They're not fringe ideas when you go to a Trump rally today. These ideas are on the center stage.”

Thompson’s documentary initially premiered in early 2021, and an updated version, airing GBH 2 on Tuesday, Jan. 4, looks at whether another insurrection is possible as more far-right movements gain traction in online and offline spaces. He notes on Boston Public Radio that far-right, white supremacist movements picked up steam starting in 2017, and rooting them out is difficult in systems that weren’t designed to eradicate pervasive bias.

Multiple participants in the Capitol riots, as well as supporters of the attack, have been elected to public office in the wake of the attack. Matthew Lynch, whose selfie at the Capitol riots circulated in local Facebook groups, was elected to the Braintree School Board in just months after the attack. He has not been charged with a crime.

When asked about a recent AP investigation that found that decades of Pentagon efforts to rid the military of bias and extremism had failed, Thompson points out that the legal framework governing all service members lacks mechanisms to quantify and categorize hate crimes.

“The military has been unable to track service members engaged in extremist activity and service members engaged in criminal conduct around extremist activity, because it doesn't have any tracking system, and because it doesn't have a specific prohibition in its military justice code for it,” Thompson said. “So they don't know how many people are involved in this sort of activity.”

Due to recent spikes in white supremacist, extremist activity, Thompson says that the FBI has begun to pay close attention to far-right domestic extremism.

“What you've seen is a massive ramp-up in attention, sophistication, intelligence and, you know, general aggressiveness from the Bureau on these types of characters,” Thompson said. “That being said, when you look at January 6, it is absolutely clear that there were big intelligence and law enforcement failures there.”

The updated version of “American Insurrection,” airing at 10 p.m. on GBH 2, includes new interviews with members of the House Select Committee on Jan. 6 and far-right Capitol riot participants.

A.C. Thompson is a senior reporter at ProPublica and a FRONTLINE correspondent. “American Insurrection” airs on Jan. 4 at 10 p.m. EST on PBS, and will be available to stream on FRONTLINE’s website, YouTube and the PBS video app.