Greg Guma, who worked with Bernie Sanders and later wrote a book about him, shows off old articles and photos. (Jabin Botsford/The Washington Post)

It was one of the first political events Bernie Sanders ever went to in Vermont: a 1971 discussion by a small group of left-wingers, the Liberty Union Party.

These people were not winners, in the electoral sense. The closest they had come to winning a statewide race, at that point, was losing by 56 points. So someone in the audience asked: Why don’t you become Democrats? Why not sacrifice third-party purity for a chance at actual power?

Sanders — a transplanted Brooklynite, known in Vermont for his overheated writing and underwhelming carpentry — spoke up from the crowd. The sacrifice wasn’t worth it.

“He felt strongly that you worked outside the Democratic Party,” said Jim Rader, a longtime friend who took Sanders to the meeting. “He felt there were too many compromises that had to be made, too many compromises of political principles.”

Last week, 44 years later, a group of socialists gathered in a Vermont library to have a strikingly similar debate. This time, they were deciding whether they could support Bernie Sanders himself.

Patrick St. John speaks during a meeting of the Burlington chapter of the International Socialist Organization on July 22 at the Fletcher Free Library in Burlington, Vt. (Jabin Botsford/The Washington Post)

Sanders was not at this meeting. The scruffy socialist of the ’70s — who later became a mayor, congressman and U.S. senator — is out on the campaign trail now, drawing huge crowds as a candidate for the Democratic presidential nomination.

In Vermont, the socialists’ speaker said his answer was no. The purest socialist in mainstream American politics was no longer pure enough.

Jim Ramey addresses the meeting. (Jabin Botsford/The Washington Post)

“When Sanders decided to run as a Democrat,” that was the last straw, said Jim Ramey at the meeting of the International Socialist Organization’s Burlington branch. “People on the left should not support him.”

The story of Bernie Sanders’s life in politics is the distance between those two meetings.

Sanders got his start on Vermont’s left fringe. In multiple third-party runs for office, he learned the craft of politics, which has been the only steady work he has ever had. Sanders also developed the same policy ideas that still define him: taxing the rich, expanding the safety net for the poor and weakening the influence of Wall Street.

But if Sanders kept the fringe’s ideas, he quickly discarded its small-bore tactics — and began making allies, and compromises, that would bring him bigger audiences and higher office.

The result is that Vermont is strewn with dissatisfied socialists, denouncing Sanders for perceived sins that go back to the ’70s.

And Bernie Sanders is running for president.

Jim Rader has been a longtime Sanders ally. (Jabin Botsford/The Washington Post)

“A very skilled and savvy politician,” said Rader, who later worked in Sanders’s congressional office, so close to Sanders that they shared one well-used necktie. “He’s not a purist. He’s consistent. He holds very deep convictions. But he is not a purist.”

Sanders was born in Brooklyn, the son of a paint salesman, and became involved in left-wing politics at the University of Chicago. He arrived in Vermont in a wave of newcomers, back-to-the-landers. They didn’t make a habit of asking one another where they had come from.

“He was poor as a church mouse back then . . . living in an apartment that I always referred to as dark, stark and cluttered,” said Darcy Troville, a friend from those early days. Sanders had been divorced years before. He had a son, whose mother and he never married. “I was wondering how he ended up with this baby alone. I didn’t know what he did for work,” Troville said.

If Bernie Sanders had a great talent at that time, it was not obvious.

He wrote for the Vermont Freeman, a counter-culture newspaper, for $10 or $15 a story, including an especially strange piece about dark sexual fantasies. Sanders also did some carpentry. Nobody remembers the writing or the woodworking well.

The thing Sanders was good at, it turned out, was politics.

But even that wasn’t clear right away.

John Bloch has known Sanders for decades. (Jabin Botsford/The Washington Post)

“We didn’t have a chance in hell,” John Bloch said, recalling a meeting of the Liberty Union Party in 1971, when members were seeking nominees to run for the U.S. Senate. “I said, ‘Is there anybody that can be lion bait for the Senate race? We need a body.’ ”

Sanders volunteered.

In his first radio interview as a candidate, he later recalled, his nervous knees knocked the table so loudly that the microphone picked it up. “A strange thumping noise traversed the airwaves,” Sanders wrote in his 1997 autobiography, as the sound engineer waved at him to stop it.

The message that Sanders used in that campaign is present in this one. “Wealth=power, lack of wealth=subservience. How could we change that?” he recalled in his autobiography, called “Outsider in the House.” “The ideas I was espousing were not ‘far out’ or ‘fringe.’ Frankly, they were ‘mainstream.’ ”

Maybe. But Sanders wasn’t. He got 2 percent of the vote.

In 1974, Sanders ran for Senate again. Four percent.

In 1976, he ran for governor. Six percent. He was getting better at debates and retail politics. And at this rate, he would be up to an electoral majority in only . . . 44 more years.

So, in 1977, Sanders quit the party.

In the media, he called Liberty Union “a failure.”

“I didn’t really think he had a right to do that,” said Doris Lake, a former House candidate who had campaigned alongside Sanders in his first race. She meant bad-mouthing the party. “We were still keeping it alive.” Not for the last time, Sanders had alienated one of the true believers with whom he had started out.

Old Sanders campaign buttons. (Jabin Botsford/The Washington Post)

“Enough was enough,” Sanders told himself, he recalled in his autobiography. “My political career was over.”

Trouble was, his other career was worse.

Sanders made slide shows with audio for Vermont schools. But his operation was so painfully low-tech that he was stymied by the need for a “beep” to tell the teacher to advance to the next slide. He couldn’t afford a professional beep. “He tried banging a pot lid with a spoon,” friend Terry Bouricius said. That wasn’t a beep. Finally: “His son’s walkie-talkies, if you pushed both the buttons at the same time, it would make a beep sound.”

Sanders also tried to be a documentary filmmaker, with a movie about a personal role model: Eugene V. Debs, leader of the Socialist Party of America. Sanders did his hero’s voice himself: “One class is small and rich and the other lahwge and poor,” he read in his Brooklyn accent, according to audio discovered by Mother Jones magazine. He continued: “One consists of capitalists, and the other of work-uhs.”

Debs was from Indiana.

“I said, ‘Bernie, you’re not going to sell this thing. The soundtrack, Debs has a Brooklyn accent you can cut with a knife,’ ” Bloch, his friend, remembered saying. Vermonters wouldn’t understand it. “He said, ‘They’ll luuhn.’ ”

It still wasn’t much of a living. Sanders’s landlord raised his rent, and he moved in with a friend.

Then that friend, a University of Vermont professor, persuaded him to go back into politics — running for Burlington mayor as an independent, without the baggage of a larger party behind him. This time, Sanders focused on local issues: a waterfront development, fighting a tax increase, keeping a hill open for snow-sledding.

He won by 10 votes. That year, Sanders recalls, his friends chipped in and bought him something a mayor needs: a leather briefcase. He was 40 years old.

Sanders first faced strong opposition from Republicans and Democrats. He did some things that his old allies liked — he hung a picture of Debs in City Hall, he criticized U.S. policy in Central America, he set up an office to increase affordable housing, and he tried make cable TV cheaper for the poor.

But he still alienated some on the left, at times, by acting like a mayor instead of a socialist.

In 1983, for instance, some of Sanders’s old allies planned to block the gates of a General Electric plant in Burlington that made guns for military helicopters. They would demand that the factory start making something peaceful instead.

Greg Guma worked with Sanders and later wrote a book about him. (Jabin Botsford/The Washington Post)

“He said he would have us arrested,” said Greg Guma, who had known Sanders since 1972. “Then the day came. And he did.” The socialist mayor sat quietly on a guardrail, watching them being handcuffed.

In the same period, Sanders also began a political relationship with the Democratic Party. He still denounced the party as ideologically bankrupt, part of a closed and corrupt two-party system.

But, when big elections came, he also campaigned for its candidates, as he did for Walter Mondale in 1984.

That lost him another socialist ally.

“The friendship could not stand him storming around the state for Fritz Mondale,” said Peter Diamondstone, one of Sanders’s friends from the Liberty Union Party and Doris Lake’s husband.

In the good old days, Diamondstone used to stay over at Sanders’s house in Burlington, and the two men stayed up late shouting political arguments at each other.

One such row had been over whether all children should be allowed to vote. Diamondstone said yes. Sanders said only after puberty. “I said, ‘Waddya want, the town clerks to start doing examinations?” Diamondstone remembered yelling.

Now, that was over. Diamondstone staked out a Mondale event. He caught Sanders coming in and handed his friend a leaflet that called him a “Quisling.”

Since then, as Sanders rose through the political ranks, Diamondstone has continued to run as a third-party candidate for state and federal offices. He has run 16 times. He has never won. He has never even cracked 6 percent.

“It was who we were. I mean, he was the best politician. But I watched how he changed. And those changes seemed to be related to moving to the right” to build a bigger following, Diamondstone said. “I was myself, and he was himself. He became a Democrat. And I stayed where I was.”

An old Bernie Sanders poster is seen at the home of Greg Guma in Burlington, Vt. (Jabin Botsford/The Washington Post)

Sanders served as mayor of Burlington for eight years, leaving office in 1989. Later that year, he and Frank Kochman — his old publisher, from his threadbare days as a $15-per-story writer — found themselves alone at a party, looking out over Lake Champlain.

“He’s looking off in the distance, and he says . . . ‘I think I ought to run for governor or Congress.’ I said, ‘Bernie, I don’t think that you’ll ever get elected governor,’ ” Kochman said.

The state might not want to be governed by a socialist. But it might send one to Washington. “Congress,” Kochman said. “I think you got a real shot.”

Sanders ran, and now it appeared that his courting of the Democrats paid off.

Their big guns stayed out of the way, apparently assured that Sanders was close enough to being a Democrat already. With the help of the National Rifle Association, which hated the Republican incumbent, Sanders won.

His association with Democrats continued to pay off.

By 1991, Sanders — although still officially an independent — was part of the Democratic caucus in Congress, climbing the party’s seniority ladder. He has not faced a serious challenge from a Democrat in all the elections since.

“Why would you run against him, you know what I mean?” said Jeff Weaver, a longtime Sanders staffer and current campaign manager. For Democratic leaders in Congress, he said, Sanders “was a more reliable vote than a lot of other people down there who had a ‘D’ after their name.”

But, in this election, Sanders is running as a Democrat — officially, fully, within the party system he decried for so long. Sanders said the party’s structure makes it easier to get on ballots, into debates and into the media.

He has said that if he loses in the Democratic primary, he will not run as an independent.

“His decision to run this election in the Democratic primary was completely informed by Ralph Nader,” said John Franco, a longtime friend who is a lawyer in Burlington. He said Sanders did not want to draw votes away from a Democrat and elect a Republican in the process, as happened when Nader ran and George W. Bush won in 2000. “That really turned out swimmingly,” Franco said.

What about those on the left who think Sanders has sold out by refusing to go it alone?

“Frankly, those people — they have their meetings in a phone booth,” Franco said.

Or, at least, in an upstairs meeting room at the Burlington public library.

An International Socialist Organization poster in Burlington, Vt. (Jabin Botsford/The Washington Post)

There were 28 people there at the International Socialist Organization meeting Wednesday night. They called one another “comrade.” They praised Nader for having the guts to challenge the two-party system in 2000. No matter who got elected instead.

“My first vote was for Ralph Nader,” said Patrick St. John, 32.

“Good for you!” somebody called out, and meant it.

Ramey, a forklift operator for a chocolate company, was in charge of answering the question: “Should the Left Support Bernie Sanders?” He listed some of Sanders’s policy goals: a higher minimum wage. Equal pay for women. Free college tuition. A single national health-care system.

“I’m not going to lie. That would be pretty good,” Ramey said.

But it wasn’t good enough, he said, because of Sanders’s choice of tactics: He was running as a Democrat. Which meant that he could lose and deliver his voters to Hillary Clinton, a mainstream Democrat with ties to Wall Street and big business. Deliver them to the system they all wanted to defeat.

“Warts and all, the [Sanders] campaign has a lot going for them,” Ramey said. “But the Democratic Party is not a wart.” It is a fatal flaw, he said.

So, if Sanders wasn’t good enough, what should the socialists do? They didn’t settle on a plan. After an hour of discussion, a man in a straw hat stood up.

“I’m tired of being powerless!” said Albert Echt, 66. He wanted to support Bernie Sanders, warts and all. “Let’s jump on Bernie’s coattails. . . . That would actually be doing something, instead of sitting around!”

The room was not moved. The moderator called on the next person who had raised a hand. Echt, frustrated, walked out.

“They’re such fools!” he told a reporter, in a too-loud whisper, as he left.

The meeting broke up amicably without him. In the next week, Sanders was planning big rallies in Iowa and Louisiana. The socialists had a plan to meet again on Thursday in Burlington.

Alice Crites contributed to this report.