Proud Boys saw surge in membership after Trump's debate message, former member testifies

Former Proud Boys official Jeremy Bertino -- who last year pleaded guilty to seditious conspiracy related to Jan. 6 -- took the witness stand in Washington on Tuesday in the seditious conspiracy trial of the far-right group's principal leadership.

Bertino said interest and membership requests for the Proud Boys surged after then-President Donald Trump addressed the group by name during a 2020 presidential debate.

"Proud Boys, stand back and stand by," Trump said at the time. "But I'll tell you what, I'll tell you what, somebody's got to do something about [leftist movement] antifa and the left because this is not a right-wing problem."

Bertino, whom the government has said joined the Proud Boys in 2018 and served as vice president of his local chapter, testified on Tuesday that he was "stunned and excited" to hear Trump mention the group.

His baseless belief that the 2020 election was stolen continued to grow in the months and weeks leading up to Jan. 6, 2021, a view that he shared with other members of the Proud Boys, he said. (He previously testified before the House Jan. 6 committee.)

The Proud Boys' former leader Enrique Tarrio and four associates are on trial facing charges of seditious conspiracy against the U.S. over their involvement with the Jan. 6 attack on the U.S. Capitol.

They have all pleaded not guilty, and their attorneys have argued some of their conduct was constitutionally protected speech.

"Mr. Tarrio is looking forward to the start of the trial," his defense attorney, Nayib Hassan, previously said in a statement to ABC News. "We look forward to making our presentation of the evidence and acquitting Mr. Tarrio of the government's allegations."

On the stand, Bertino described the mindset of him and other Proud Boys.

"Everything seemed like a conspiracy at that point," he said.

The group also held strong views against anyone they deemed to be part of "the left" or "antifa," a reference to far-left protestors who take drastic and sometimes violent measures to, they say, oppose fascism.

"I believed they were the foot soldiers of the left," Bertino testified. He went on to note that the Proud Boys believed they were the "foot soldiers of the right."

Under questioning by a government prosecutor, Bertino's testimony painted a picture for the jury which connected the Proud Boys' hatred of "antifa" with their involvement in Jan. 6. Bertino said he believed at the time that "antifa" was funded by Democrats.

The Proud Boys call themselves "Western chauvinists," believing that they are responsible for "creating the modern world."

Defense attorneys on Tuesday objected to several questions the government posed to Bertino, especially when he was asked to describe the collective views of the group.

But Bertino testified to having a close and friendly relationship with Proud Boys leadership before ultimately deciding to leave the group.

Prior to his departure, Bertino led recruitment for the Proud Boys in North Carolina and was close to the highest levels of the group's leadership. He was not in Washington on Jan. 6 and was recovering from a stabbing that occurred at a previous demonstration the Proud Boys had attended.