A fan of Charles Manson and follower of Hitler, James Mason published essays in the 1980s that now act as the inspiration for a militant neo-Nazi group linked to multiple murders in the U.S.

“Revolutionary discipline must mean that WE will be the single survivor in a war against the System,” Mason wrote in 1985. “A TOTAL WAR against the System.”

But nowadays, Mason isn’t waging war with the system. He is, in fact, dependent on it.

The 67-year-old white supremacist lives in a government subsidized apartment in Denver and eats at soup kitchens.

In a brief interview last week, a few days after he was spotted picking up a meal at a city-run center for “homeless and hungry seniors,” Mason said he sees no contradiction between his writings and his lifestyle.

“Guerilla warfare, man. Guerilla warfare,” Mason told NBC's Denver affiliate KUSA. “You’ve gotta take what you have to get what you need.”

Mason’s old writings have gained new life with the rise of the Atomwaffen Division, a white supremacist group bent on overthrowing the government through terrorist acts and guerrilla warfare tactics.

The extremist organization, whose name means “atomic weapons division” in German, formed in 2015 in the now defunct neo-Nazi online forum Iron March. Experts say it’s a largely decentralized group, small in size but large in ambition.

“Members see themselves as soldiers preparing themselves for an impending race war,” said Joanna Mendelson, senior investigative researcher with the Anti-Defamation League’s Center on Extremism.

“They create this apocalyptic worldview that their future is hanging by a thread. They paint a picture of a genocide and that they see themselves as needing to rise up against the tide that seeks their destruction.”

In the past two years alone, men with ties to Atomwaffen have been accused of killings in Florida, California and Virginia.

In the California case, an Atomwaffen Division member named Samuel Woodward was arrested and charged with fatally stabbing Blaze Bernstein, a gay, Jewish student, inside a park in Orange County in January 2018. Woodward pleaded not guilty and is awaiting trial.

Samuel Woodward was arrested in connection with the death of 19-year-old Blaze Bernstein. Orange County Sheriff's Department

Experts say the group has greatly expanded the influence of Mason and his decades-old writings. His SIEGE newsletters, which have been posted on numerous online forums and compiled into a 563-page book, serve as Atomwaffen’s ideological foundation.

“The enemy today is the U.S. Government itself and it is, by every standard of measure, the most evil thing that has ever existed on earth,” Mason wrote in a newsletter published in August 1980.

“Can you picture a scenario like this: that great 'Silent Majority' has at last gotten fed up, found its wits and given the Nazis or the Klan a voter mandate,” he wrote in a latter section. “The Jews, the Blacks, and the assorted fanatic Reds, etc. least of all to mention the entrenched Capitalist System manned largely by sick, liberal Whites give up, say it was a fair fight, shake hands and turn it all over to us. It's just too crazy to contemplate.”

Mason had largely faded into obscurity in the past two decades, but his writings are now seen as helping to fuel a rise in far-right extremism across the globe.

Authorities in Germany and the U.K. told NBC News that Mason is influential among radicals in both countries. A British intelligence official said Mason’s writings served as inspiration for multiple far-right extremists who were arrested for unspecified crimes.

The FBI declined to comment.

James Mason holds a beer glass emblazoned with a swastika in an undated photo.

Mason’s newfound relevance marks a sudden turn in the life of a man whose days of notoriety seemed long behind him.

“James Mason was a dried up, has-been neo-Nazi who then had his work get reappropriated and given new life especially by groups like Atomwaffen,” Mendelson said.

She described him as a “key figure within this movement and this subculture.”

“He's put on a pedestal along with Timothy McVeigh and Anders Breivik, who killed 77 people in Norway,” Mendelson said.

Mason, who was raised in Ohio and began working for the American Nazi party in his teens, has a lengthy criminal record.

In 1991, Mason served a 30-day stint in jail after he pleaded guilty to illegal use of a minor in nudity-oriented material. After his release, Mason told The Cincinnati Enquirer he took lewd photos of a 15-year-old girl at the request of her husband.

Mason moved to Colorado but his criminal problems followed. He was in and out of state prison throughout the late 1990s after he was convicted of menacing in a case involving sexual exploitation of a child, and later found to be in possession of weapons in violation of his parole.

He now lives in a red-brick apartment complex in the heart of Denver. The building is open to people who qualify for “subsidized Section 8” housing, according to postings in the lobby. Building management confirmed that all of the apartments are designated for recipients of Section 8 vouchers, a federal subsidy that helps low-income people pay their rent.

Mason’s apartment has become a magnet for Atomwaffen members. Photos posted online show Mason posing with various young men, some dressed in Nazi regalia and wearing skeleton face paint, in front of swastika flags.

One of Mason's neighbors said she wondered about all of the men heading up to his apartment.

"At first when he had young men coming up there, I thought maybe he was a pervert, to be honest with you," said the 64-year-old neighbor, who spoke on condition of anonymity.

The neighbor described Mason as "quite the gentleman" and said he helped with the yard work and eagerly took part in activities like the building's Thanksgiving gathering. But the neighbor said she was stunned when one day last summer she saw signs posted nearby with Mason's photo and a message saying a neo-Nazi lived in the neighborhood.

The neighbor went online and found his writings. "For someone who doesn’t like the government, you’re living in government housing," she said. "That right there kind of throws me."

In a typed letter, Mason initially declined an interview with KUSA for “purely tactical reasons.” But a reporter caught up with him this month.

In the interview, Mason rejected the suggestion that Nazis have been in decline since losing World War II.

“Look at the shape society is in. Look at the goddamned shootings. Look at the drugs. The suicides and the crime and everything else,” Mason said.

“I say this country lost. And decade by decade I see my beliefs proven over and over again. We’re prophets. Nobody’s listening to us, but they’re going right off the cliff thinking we’re nuts.”

Mason initially seemed to push back against the idea that his writing had inspired young neo-Nazis to commit violence. “If they were acting on my words, they wouldn’t be doing the things they’re doing,” he said.

But Mason, who insisted he's not a member of Atomwaffen, followed with an ominous and ambiguous statement about the possibility of violence.

“If you must do it, it seems to me to be only common sense that you’d want to do it right,” Mason said.

“Because it’s the end of your life. You may die out there in the street via SWAT team, or you may spend the rest of your life in the joint. Make it count for god’s sake.”

He did not elaborate.