In Washington’s respectable circles, Michael T. Flynn, the former national security adviser, is a discredited and dishonored ex-general, a once-esteemed military intelligence officer who went off the rails ideologically and then was fired a mere 24 days into the Trump administration for lying to the F.B.I. about contacts with the Russian ambassador.

As if he cared.

Where others see disgrace, Mr. Flynn, 62, has found redemption. Recast by former President Donald J. Trump’s most ardent supporters as a MAGA martyr, Mr. Flynn has embraced his role as the man who spent four years unjustly ensnared in the Russia investigation.

He was one of the most extreme voices in Mr. Trump’s 77-day push to overturn the election, a campaign that will be under scrutiny as the former president’s second impeachment trial gets underway next week. Mr. Flynn went so far as to suggest using the military to rerun the vote in crucial battleground states. At one point, Mr. Trump even floated the idea of bringing Mr. Flynn back into the administration, as chief of staff or possibly F.B.I. director, people familiar with the conversations told The New York Times.

And now, safely pardoned and free to speak his mind, Mr. Flynn has emerged from the Trump presidency much as he entered it — as the angry outsider who pushes fringe ideas, talks of shadowy conspiracies and is positioning himself as a voice of a far right that, in the wake of the Capitol riot, appears newly, and violently, emboldened.

All that has changed for Mr. Flynn are the subjects at hand, and his apparent willingness to cash in on his notoriety.

Mr. Flynn’s dark view of Islam and eagerness to cultivate President Vladimir V. Putin of Russia have given way to an embrace of QAnon, the pro-Trump conspiracy theory, and a readiness to question the very fabric of American democracy. He has swapped a government job and an obsessive focus on “radical Islamic terrorism” for selling QAnon-branded T-shirts and a new media partnership with conspiracy theorists called Digital Soldiers.

Yet his underlying message remains much the same as it was back in 2016, when he was leading chants of “lock her up” at Trump rallies: Washington’s establishment is irredeemably corrupt, and real Americans — that is, supporters of himself and Mr. Trump — are wise to it.

“This country is awake,” he declared at the pro-Trump rally in Washington last month. “We will not stand for a lie.”

It was the night before a mob attacked the Capitol, and the crowd on hand in Washington’s Freedom Plaza — some of whom would take part in the coming violence — left little doubt about where Mr. Flynn stood.

“We love you, we love you, we love you,” they chanted. None of the other speakers at the rally — a boldface-name collection of Trumpworld characters like Roger Stone and Alex Jones — got as enthusiastic a reception.

With Mr. Trump now in his post-presidency at Mar-a-Lago, a loose coalition that draws together militia members and conspiracy theorists along with evangelical Christians and suburban Trump supporters is searching for direction. Call it the alt-truth movement, and if it is to coalesce into something more permanent, it may well be, at least in part, because figures like Mr. Flynn continue to push false claims of how a deep-state cabal stole the election.

“In order for us to breathe the fresh air of liberty, we the people, we are the ones that will decide our path forward, America’s future forward,” he said at the Jan. 5 rally. “It may not be a Republican Party, it may not be a Democratic Party, it will be a people’s party.”

Martial Law

Mr. Flynn, who did not respond to an interview request for this article, spent 33 years as an Army intelligence officer, earning a reputation for being outspoken and unconventional and, in the years that followed the Sept. 11 attacks, for being unusually good at unwinding terrorist networks.

Much of that work involved mapping out loose webs of ideological fellow travelers, figuring out who gave voice to extremist ideas and who committed the violence — two groups that were not always directly tied to each other. If a similar attempt was made to map the network of people who spread Mr. Trump’s stolen-election lie that led to the storming of the Capitol, Mr. Flynn himself would probably appear as one of those leading voices for his part in riling up Mr. Trump’s supporters without taking part in the attack.

Perhaps most responsible for Mr. Flynn’s re-emergence is the conspiracy-theorizing lawyer Sidney Powell. Ms. Powell took over his legal defense in the Russia investigation after he had twice pleaded guilty in a deal to cooperate with prosecutors, and charted a combative new path. She challenged the deal and, marshaling a small army of like-minded Twitter users, recast Mr. Flynn from a turncoat into a victim, a man who had taken the fall to save his son, who was also under investigation.

It was the story of the Russia investigation as a malevolent plot that first began priming tens of millions of Americans to believe Mr. Trump’s conspiracy theories about the deep state. As one of the heroes of that narrative, Mr. Flynn became an ideal messenger when it was refashioned into the demonstrably false claim that Democrats and their deep-state allies had rigged the election.

Within days of being pardoned on Nov. 27, Mr. Flynn began sharing those views in the right-wing media.

In some appearances, he described himself as a marked man. “I gotta make sure I’m a moving target, because these son-of-a-guns, they’re after me, in a literal and a figurative sense,” he told listeners of “The Matrixxx Groove Show,” a QAnon podcast.

In an interview with Newsmax, the conservative channel, he suggested Mr. Trump could impose martial law in swing states he had lost and rerun the elections.

“People out there talk about martial law like it’s something that we’ve never done,” Mr. Flynn said. He noted that the military had taken over for civilian authorities dozens of times in American history, though he did not mention that it had never done so to help decide an election.

The suggestion horrified many of Mr. Flynn’s former compatriots in uniform. Even discussing personal politics is frowned upon in the military, and most generals see it as their duty to stay above the political fray after retirement, as well. There have long been exceptions, of course, but to many who had served with Mr. Flynn, a retired general calling for the military to help decide an American election represented a new level of recklessness.

“Mike, stop. Just stop. You are a former soldier,” Tony Thomas, a retired general who headed the Joint Special Operations Command, wrote on Twitter.

Throughout his military career, in fact, all most of Mr. Flynn’s fellow soldiers had known about his politics was that he was a registered Democrat. Then came 2016, and the sight of a retired general leading chants for the imprisonment of Hillary Clinton, a former senator and secretary of state.

When a number of generals privately and publicly urged him to dial back his support for Mr. Trump, Mr. Flynn called them “disrespectful.” If they could use their titles to get on corporate boards, he could use his to back Mr. Trump, he countered in an interview at the time, saying, “I care deeply about this country.”

In any case, he said, he had never really been part of their club.

‘Flynn Facts’

Mr. Flynn has described his family as “definitely lower middle class,” and he joined the military without the West Point pedigree of many of his peers. He graduated instead from the Army’s Reserve Officer Training Program at the University of Rhode Island, a short drive from the town where he was raised.

Yet he rose to be a lieutenant general, among the most respected military officers of his generation. He helped reshape the Joint Special Operations Command at the height of the war in Iraq, and ran military intelligence in Afghanistan during the Obama administration’s troop surge. In 2012, President Barack Obama named him director of the Defense Intelligence Agency.

Then his career unraveled. After only two years, he was forced out when his attempt to reform the sprawling agency left subordinates squabbling and his superiors alarmed.

Mr. Flynn, though, claimed that he had been fired for refusing to toe the Obama administration’s line that Islamist militants were in retreat. His position was vindicated with the rise of the Islamic State, and Mr. Flynn quickly became something of a cult figure among conservatives for what they saw as his brave stand against the Obama administration’s perfidy.

As his relentless focus on Islamist militancy intensified, his views veered hard to the right. He argued that militants posed a threat to the very existence of the United States, and at times crossed the line into outright Islamophobia, tweeting “fear of Muslims is RATIONAL.”

In Mr. Trump, he found a presidential candidate who shared his dark and conspiratorial view of Islam.

The similarities between the two men did not end there: Both shared a fondness for Twitter and often exhibited a loose relationship with the truth. When Mr. Flynn ran the D.I.A., his dubious assertions were so common that subordinates came up with a name for them: “Flynn facts.” (In January, he was among those banned from Twitter with Mr. Trump.)

So it was no great stretch to see Mr. Flynn hurling conspiracy theories about an election that federal election-security experts considered among the best run on record, and for Mr. Trump to listen.

Last Dec. 18, Mr. Flynn participated in a raucous White House meeting in which Ms. Powell proposed that the president appoint her as a special counsel investigating voter fraud. Mr. Trump at one point also raised the idea of putting Mr. Flynn in charge of the F.B.I., and later suggested making him chief of staff for the final weeks of his administration, according to Trump and Flynn associates familiar with the conversations, all of whom spoke on the condition of anonymity to avoid angering either man.

Whether the president was serious about either idea is an open question. But Mr. Flynn shot them down, saying he needed to focus on paying off millions of dollars in legal debts he had amassed fighting off the Russia investigation.

Joining the Fringe

His plan for paying those bills appears to rely on leveraging his public persona into cold, hard cash. There are the T-shirts and other merchandise, which he is selling through a company called Shirt Show USA. The website features shirts emblazoned with #FightLikeAFlynn and camo trucker hats with the emblem “WWG1WGA,” a reference to a popular QAnon motto, “Where we go one, we go all.”

Then there is his new media venture, Digital Soldiers, which will publish reader-submitted stories. Mr. Flynn is building it with UncoverDC, a website that has pushed QAnon and conspiracy theories about the Covid-19 pandemic and President Biden.

The tenor of Digital Soldiers is unmistakably QAnon, a movement centered on the claim that Mr. Trump, secretly aided by the military, was elected to smash a cabal of Democrats, international financiers and deep-state bureaucrats who worship Satan and abuse children. The supposed dishonesty of the mainstream media is central to QAnon, and Digital Soldiers — a phrase followers often use to describe themselves — represents Mr. Flynn’s fullest embrace of the movement to date.

“Digital Soldiers from all over the world have stepped up to fill the void where real journalism once stood,” the website says.

This past summer, Mr. Flynn posted a video of himself taking QAnon’s “digital soldier” oath. To many of the movement’s followers, Mr. Flynn ranks just below Mr. Trump. Some have speculated that he is the mysterious figure known as “Q,” the purported government insider with a high-level security clearance who began posting cryptic messages in 2017 about the deep state trying to destroy the president.

“They really take his word as gospel,” said Travis View, a close observer of the movement who hosts the podcast “QAnon Anonymous.” “In the mythology, they often say that he knows where the bodies are buried, and that’s why they tried to railroad him over Russia.”

The phrase “digital soldiers” is drawn from a speech Mr. Flynn gave shortly after the 2016 election during which he inadvertently laid the groundwork for the conspiracy theory. He compared the Trump campaign to an insurgency — a theme that QAnon adherents would later adopt for themselves — with “an army of digital soldiers.”

“This was irregular warfare at its finest — in politics,” he said.

Among QAnon faithful, who believe that Mr. Trump and others use public statements to send secret signals, Mr. Flynn’s speech is considered something of a foundational text. And now, in naming his new media outlet Digital Soldiers, many believe he is sending them a message to carry on, even though Mr. Trump left office before the predicted apocalyptic showdown with his enemies — know as “the storm” — could come to pass.

As one QAnon devotee noted in an IRC channel, a relatively dated online chat room technology favored by those particularly suspicious of possible surveillance, “If they kill or capture Trump, Flynn can still carry out the mission.”

“The troops march to the beat of his drum,” wrote the user, who went by the screen name “specialist.”

The plan, the user added, was “masterful.”

Ken Vogel and Maggie Haberman contributed reporting.