Elias Demetracopoulos was a fascinating character — World War II resistance fighter, journalist, opponent of the military junta in Greece and, ultimately, a political exile in the United States. Today, though, he is all but forgotten.

In a new biography, James H. Barron seeks to rectify that. “The Greek Connection: The Life of Elias Demetracopoulos and the Untold Story of Watergate” (Melville House) portrays a larger-than-life figure who could have altered the course of American history if his warnings about illegal Greek financial contributions to Richard Nixon’s 1968 presidential campaign had been made public. As Barron reveals, The Boston Globe came tantalizingly close to breaking that story — but it went untold until years later.

Given what we already know about Nixon’s attempts to sabotage the Vietnam peace talks during the 1968 campaign, the new details about secret Greek money described by Barron can only add to Nixon’s reputation as a corrupt, cynical politician willing to wade illegally into international affairs if he thought it would benefit him. Watching President Donald Trump clumsily bulldoze his way over the path blazed by Nixon calls to mind Marx’s observation that “history repeats itself, first as tragedy, second as farce.”

Barron is a lawyer and journalist based in the Boston area whose career stops included The Boston Phoenix, and who has written for The Christian Science Monitor, The Boston Globe, The New Republic and The European. He was the first book review editor for Campaigns & Elections. Barron is also a founding advisory board member of the New England Center for Investigative Reporting, now the WGBH News Center for Investigative Reporting. His wife, Marjorie Arons-Barron, is the retired editorial-page editor at WCVB-TV (Channel 5) and a well-known local blogger.

The following email interview has been lightly edited.

Q: What were the circumstances that led you to tell Demetracopoulos’ story?

A: Serendipity. I was rushed to the ER by ambulance in 2007. Before they figured out my problem, I tried to quell my fears by imagining an idyllic morning on the island of Mykonos 40 years before. Afterward, I thought about why, at that perilous moment, my mind went to Greece in 1966.

I briefly considered writing a novel set there, but I’m not a fiction writer. I was fascinated by the Bostonian Greek tycoon Tom Pappas’ role in the 1968 election and started to write about him. In 2009, I told the legendary investigative reporter Sy Hersh about my project. He advised me to focus instead on Elias Demetracopoulos, the person who tried to blow the whistle on Pappas.

After meeting Elias in Washington, I realized this episode was a small part of a remarkable life, beginning with his days as a 12-year-old involved in the Greek resistance. He was captured, tortured, imprisoned and sentenced to death by the Nazis. Later, as an aggressive, fiercely independent journalist, he fled Greece when a military junta seized power in 1967, escaping to the U.S. over State Department objections.

Q: You write that Demetracopoulos went to Democratic Party operative Larry O’Brien in 1968 with information that Richard Nixon’s presidential campaign had received a secret $549,000 payoff from the Greek junta. You also speculate that O’Brien didn’t inform President Lyndon Johnson, even though it could have led to Nixon’s defeat at the hands of Hubert Humphrey. Why do you think O’Brien sat on it?

A: I explore different theories. O’Brien trusted the message, but not the messenger. Before fleeing to the U.S. in 1967, Elias had been a scoop-hungry reporter whose exposés had so angered American officials that the CIA and State Department tried to destroy his reputation and effectiveness, often placing false information in his intelligence files. JFK press secretary Pierre Salinger passed lies and unjustified speculation to O’Brien and others that, beneath his charming exterior, Elias was a communist who secretly worked for “the other side,” and should not be trusted.

Joe Napolitan, Humphrey’s media adviser, begged to use the Pappas illegal foreign money revelation in ads. O’Brien said no. David Broder of The Washington Post told me that, given how close that election was, Elias’ disclosure would have been a “bombshell” that could have changed the outcome. Imagine history with no President Nixon and no Watergate.

Q: There’s a great Boston Globe angle in your story. You write that Washington bureau chief Bob Healy took Demetracopoulos’ tip to editor Tom Winship, who in turn assigned the story to Christopher Lydon. Lydon ended up writing a profile of Tom Pappas, who was part of Nixon’s campaign as well as a bagman for the junta, but he was unable to prove there had been a payoff. Did the Globe ever try to revisit that story?

A: Healy’s tip came informally from CIA agents, not Elias, indicating that American intelligence at some level knew about the Greek junta plot to bribe the Nixon-Agnew campaign. O’Brien told Elias that, because the matter was so delicate, if he wanted O’Brien to go to LBJ to expose the scandal, Elias must not talk to the press. And he didn’t.

Lydon wrote about the Greek money rumor in the Globe but said the charge was “unsubstantiable.” Lydon interviewed Pappas, who denied the charges, and O’Brien’s press secretary, who said nothing to Lydon about Elias — despite Elias’ detailed revelations to O’Brien, his offers to provide corroborating witnesses in Athens, and even to fly some witnesses to the U.S. More problematic were non-Globe reporters like Gloria Steinem, who summarily dismissed the Greek money rumors as an illegality the frontrunning “New Nixon” would not stoop to commit.

The Globe never revisited the story. Elias moved on, considering his efforts to blow the whistle on Pappas a distraction from his principal fight to restore Greek democracy. Lydon later joined The New York Times, where he met Elias and found him to be a credible source.

Q: The title of your book refers to “the untold story of Watergate.” As you explain, the gang of Nixon operatives who broke into O’Brien’s office at the Watergate complex may very well have been looking for O’Brien’s notes on what Demetracopoulos had told him four years earlier. That would place Nixon’s relationship with the Greek junta at the center of both his 1968 and 1972 campaigns. How does that change our understanding of the Watergate scandal and the Nixon presidency?

A: Greece was peripheral to Nixon’s foreign policy interests, save for his preferring a staunch anti-communist dictatorship to a messy democratic government, human rights be damned, and as a source for illegal campaign funds to be milked by his tycoon fundraiser Tom Pappas.

Watergate is a metaphor for abuse of power during the Nixon years. The scandal didn’t begin with the planning for the June 1972 break-in. Its roots are in the illegal financing of the 1968 election, the potential disclosure of which caused, in the words of the historian Stanley Kutler, the “most anxiety” in the Nixon administration “for the longest period of time.”

Elias’ 1971 congressional testimony against Pappas pushed Nixon’s henchmen into overdrive and led to schemes to have Elias deported, not to mention looking away when the Greek junta plotted to have Elias kidnapped and killed. The sole opportunity to expose the reasons behind the Watergate break-in before the election was stopped because of untruthful attacks on Elias’ reputation.

There is strong circumstantial evidence that at least part of what the burglars were directed to find was whatever derogatory information the Democrats had on Nixon, especially financial documents related to foreign contributions.

Q: Demetracopoulos was a well-known, well-connected figure for many years, yet today he is all but forgotten. What do you think is the single most important lesson of his life and career?

A: Fame is fleeting. Two of the most influential columnists of that time, Walter Lippmann and Joseph Alsop are also largely forgotten today.

The central takeaway from Elias Demetracopoulos’ life is that one intrepid individual, against great odds, can make a difference — but standing up to abusive governments often entails profound risks, great personal sacrifices, and a lifetime of relentless attacks and harsh consequences.

To be a whistleblower requires the courage to jeopardize your career and even risk your life. But doing so can influence history.

WGBH News contributor Dan Kennedy’s blog, Media Nation, is online at dankennedy.net.