When Steve Bannon heard that he was, after all, going to face charges last week for allegedly ripping off contributors to a multimillion-dollar fund to build a wall on the Mexican border, he claimed it was a sign of his success.

Donald Trump’s former strategist said his arrest on Thursday was an attempt to shut down his War Room pod and video cast because it is driving grassroots support for the former president’s Make America Great Again (Maga) movement and reshaping the Republican party ahead of the midterm elections.

“They are coming after all of us, not only President Trump and myself. I am never going to stop fighting,” he said.

That much was apparent from Bannon’s final broadcast before his arrest as he let loose against the Biden “regime” and “social media oligarchs” he accused of conspiring to fix elections for the Democrats. For Bannon, the endless war is between “people in our posse” and Joe Biden’s “global attack on Maga”.

The audience for this daily assault on reality is not as large as it once was. YouTube blocked the War Room two days after the storming of the Capitol in January 2021 for falsely claiming the presidential election was stolen. Exact numbers of listeners are hard to come by but the programme has been downloaded millions of times and still regularly appears in the top 50 most listened to podcasts in the US, at times reaching No 2 in Apple podcasts about American politics.

From there, the War Room appears to be having an impact far beyond the sight of most Americans, as Bannon pushes a strategy for Maga supporters to infiltrate the Republican party before the midterms and 2024 presidential election.

But now the 68-year-old architect of Trump’s 2016 presidential election victory, and briefly a White House aide, could be stopped in his tracks by his legal problems. Bannon already has a conviction for contempt of Congress under his belt for refusing to testify over his role in the attack on the Capitol that could send him to jail for months when he is sentenced in October.

The latest charges put the white nationalist back on the hook for alleged crimes for which he was pardoned by Trump in the last hours of his presidency. That pardon covered only federal crimes and New York state has waded in to accuse Bannon of stealing $1m from donations to the We Build The Wall campaign to help construct an anti-migrant barrier on the US border with Mexico. Two other men have already pleaded guilty in connection with the alleged fraud and face lengthy prison sentences.

Madeline Peltz, who has followed Bannon’s broadcasts for the past two years for Media Matters, which monitors conservative and far-right commentators, said that for all his problems, it would be a mistake to write off the populist agitator.

“The big picture shows that you can never really count out Steve Bannon, both because of the trajectory of his career as well as the status of the movement in which he is a prominent figure,” she said.

Bannon has maintained that status by keeping the myth of the stolen 2020 presidential election front and centre in his broadcasts as key to engineering Trump’s comeback if he runs again in two years.

But Bannon’s most important role at present may be his championing of what is known as the “precinct strategy”, which seeks to take control of the Republican party from the bottom up, getting Trump supporters to take low-ranking, often vacant, positions within local branches. They are then in a position to select more senior party officials and to influence decisions such as the staffing of elections and selection of candidates, and ultimately to move up the party ranks.

Maga activists are also targeting school boards and poll monitoring positions.

“We’re going to take this back village by village … precinct by precinct,” Bannon said in one of his shows pushing the strategy.

ProPublica contacted dozens of Republican party county leaders across the US who reported significant increases in membership applications that appear tied to the precinct strategy.

Peltz said that the consequences could be with America for years.

“If Bannon is successful in shoehorning grassroots activists, which it appears that he is, he could have loyalists controlling the levels of power within the Republican party and, even more concerning, in election administration. That could be almost impossible to unwind for years and decades to come,” she said.

For all that, Bannon faces challenges.

As he sought to remain politically relevant after a brief and turbulent stint as a White House aide at the beginning of Trump’s presidency, Bannon launched a far-right group in Europe, the Movement, that rapidly failed.

He also fell out badly with Trump, with the president saying that his former strategist had “lost his mind” after Bannon was quoted as describing a meeting between one of the president’s sons and a group of Russians as “treasonous”. Bannon backed off but the damage was done and it cost him his position running the far-right Breitbart News after a major financial backer withdrew support over the Trump comments.

Bannon reingratiated himself in part by launching the War Room from a Washington townhouse three years ago to campaign against Trump’s impeachment. Within a few months, it evolved into War Room: Pandemic to exploit uncertainty and fear about the spread of coronavirus. Eventually, it broadened as a platform for Bannon’s rants about whatever was frustrating him.

Bannon’s influence is not without its limits. Most of the candidates he backed in the 2022 Republican primaries lost. Peltz said that he is also financially vulnerable.

“A big weakness is that he’s super desperate for money. His billionaire benefactor, Gou Wengui, declared bankruptcy. Since then the whole show has turned into a big rightwing direct-to-consumer ad for a variety of scammy projects, including gold, MyPillow, satellite cellphones, prepper supplies. That’s a sign that he’s not in a good position,” she said.

Then there is the prospect of prison. He would not be able to broadcast the War Room from his cell, although others might hold the fort if he was serving a relatively short spell in jail. A longer prison sentence of several years, which is quite possible if he is convicted on the fraud charges, would be a different matter.

Still, Peltz said that a prison sentence could bolster Bannon’s credibility on the right. “He ultimately will be a bigger hero among the Maga crowd than ever, and I think that his sort of profile in American politics could take off from there,” she said.