The campaign signs had been printed. The launch party was scheduled. And the African American activist was ready to join the race for Charlottesville City Council.

He had sent out a news release announcing his intention to run the night before the party, on Jan. 7. But just 24 hours later, the campaign was over. Standing before his supporters, the black candidate said he would not be kicking off his campaign after all.

Now, federal prosecutors say they know why: A white supremacist sent him a slew of violent threats the night he announced his candidacy.

Daniel McMahon of Brandon, Fla., was arrested Wednesday and charged with bias-motivated interference with a candidate for elective office, accused of cyberstalking and threatening the candidate to the point that he dropped out of the race, prosecutors said. The candidate is identified in court documents only as “D.G.” but the Daily Progress reported that the details in the charges match the halted campaign of deacon and activist Don Gathers. The co-founder of Charlottesville’s Black Lives Matter chapter, Gathers also served on a committee dedicated to relocating Confederate statues in the wake of the deadly Charlottesville Unite the Right rally in 2017.

McMahon, 31, allegedly threatened the candidate with violence because he was a black man campaigning for office, causing him “to fear death and serious bodily injury” if he were to go forward with his campaign, prosecutors said.

“As alleged in the indictment, this defendant was motivated by racial animus and used his social-media accounts to threaten and intimidate a potential candidate for elective office,” U.S. Attorney Thomas T. Cullen, of the Western District of Virginia, said in a statement. “Although the First Amendment protects an individual’s right to broadcast hateful views online, it does not give license to threats of violence or bodily harm.”

McMahon’s attorney told the Associated Press that McMahon “categorically denies all of the allegations.”

According to the indictment, McMahon frequently promoted beliefs on the Internet that “white people are superior to members of other racial, ethnic and religious groups.” On social media, he goes by the alias “Jack Corbin,” the AP reported — including on Gab, a social network popular with far-right users, where “Jack Corbin” identified himself as a “God d--- fascist."

That network is also where Robert Bowers, the accused mass shooter at Tree of Life synagogue in Pittsburgh, reportedly encountered him.

Ahead of the shooting that killed 11 people in October 2018, Bowers interacted on Gab with “Jack Corbin” more than any other user, according to an analysis by the Network Contagion Research Institute, a nonprofit organization studying hate on social networks. Bowers allegedly shared Corbin’s posts advocating for violence against antifa and shared racist, homophobic commentary, including one post from Corbin that said, “Whites have a right to exist,” but gay people don’t.

Right Wing Watch, a project of the liberal advocacy group People For the American Way, identified McMahon as Jack Corbin in 2018. It found that McMahon “showered praise” on Bowers after his attack, allegedly writing, “God bless that man.” And it found he praised James A. Fields Jr — the avowed neo-Nazi who was sentenced to life in prison after he rammed his Dodge Challenger into a crowd of counterprotesters at the Unite the Right rally in Charlottesville, killing Heather Heyer. To intimidate antifascists, Right Wing Watch reported, he would frequently invoke Fields.

“Hey Antifa, it’s simple,” Corbin wrote on Gab, according to Right Wing Watch. “Wanna know how to not get Dodge Challenged or shot? Don’t attack Right Wingers ever.”

Gathers decided to run for city council in Charlottesville as the city was recovering from the violence of the August 2017 Unite the Right rally. Dozens of white nationalists, white supremacists and neo-Nazis had descended on the city, chanting “Jews will not replace us” as they hoisted torches.

The rally had come in response to a vote by the Charlottesville City Council to remove a statue of Robert E. Lee in a park named in his honor — and Gathers had chaired the city’s Blue Ribbon Commission on Race, Memorials and Public Spaces that recommended its removal.

Announcing his candidacy, Gathers said in a Jan. 7 statement: “The toxicity that permeates our City cannot continue; Charlottesville needs healing. We need leaders driven towards unification and inclusion. We need to figure out viable, reasonable solutions to our problems: affordable housing, the lack of a true living wage, and racial inequities in education, justice, housing, and other areas.”

Gathers’s campaign slogan was “Community Driven, Community Focused,” and he had the résumé to prove it. He had worked in the trenches with Black Lives Matter, on the Charlottesville Civilian Police Review Board and was a deacon at the First Baptist Church.

But at the launch party the next day, held jointly with fellow Democratic candidate and activist Michael Payne, something changed.

Gathers said at the time that he had gone to a doctor’s appointment earlier that day, C-Ville reported. He said he was still having complications from an Oct. 14 heart attack, and thought he needed to delay his run for office for a short while before the filing deadline.

He never resumed.

It’s unclear what exactly McMahon allegedly said to the candidate or by what means, although he is alleged to have threatened the candidate through Jan. 10. Gathers also resigned from the Civilian Police Review Board the same night he canceled his run for office, the Daily Progress reported.

“The alleged targeted and racially motivated actions by Daniel McMahon were an attempt to disrupt the American political process,” David W. Archey, special agent in charge of the FBI’s Richmond Division, said in a statement.

If convicted, McMahon faces up to five years in prison on each charge of cyberstalking and transmitting threats in interstate commerce. He faces up to one year in prison each if convicted on the bias-motivated election interference charges.