Martin O'Malley, right, talks with New Hampshire State Rep. Bob Backus, left, and former State Sen. Peter Burling before a private meeting with New Hampshire Democrats. (Jim Cole/AP)

As he moved through a diner here this past week, former Maryland governor Martin O’Malley was followed by a crush of reporters. But many breakfast patrons at Chez Vachon seemed to have little idea who he was.

One woman asked if O’Malley had been governor of South Carolina. Buck Mercier, of nearby Hooksett, struck up a conversation with the Democrat about hunting and gun regulations, nodding as O’Malley told him, “I’m for common sense, man.”

“Nobody knows him,” Mercier, a retired construction worker, told a group of reporters after O’Malley had moved on. But that’s not all downside, he noted: “I don’t think anybody can say anything bad about him.”

O’Malley, who plans to formally launch his presidential bid May 30 in Baltimore, will start the race still largely unknown among voters, despite repeated visits to Iowa, New Hampshire and other early nominating states. He barely registers in polls that show Hillary Rodham Clinton as the overwhelming favorite to win the Democratic nomination, and she is expected to vastly outspend him.

And yet, some analysts and activists see a path for O’Malley — albeit narrow — to become a real factor in the race, especially if he performs well in Iowa, the first caucus state, and gains momentum going forward.

“Can he make it happen? I don’t know,” said Joe Trippi, a veteran Democratic strategist. “It’s a long, tough mountain to climb, but he’s in a position to make it happen.”

O’Malley is offering himself as a progressive, forward-looking alternative to Clinton, staking out liberal positions on issues including trade and immigration.

His party credentials could be considered stronger than those of Sen. Bernie Sanders (I-Vt.), a self-described socialist who launched his candidacy for the Democratic nomination last month, and of onetime Republican Lincoln D. Chafee, a former senator and governor from Rhode Island who is considering getting into the race. Former senator Jim Webb of Virginia is also looking at the contest.

“There are so few Democrats in the field that O’Malley might be able to emerge as Clinton’s chief challenger,” said Tom Henderson, the longtime chairman of the Polk County Democrats in Iowa.

“People want to look at the different candidates and then pick somebody,” Henderson said of Iowa, where Clinton finished third in 2008, disrupting an early sense of inevitability and opening the door for a young senator named Barack Obama.

Some powerful Democrats, including Senate Minority Leader Harry M. Reid (Nev.), say it is farfetched to expect a similar scenario this cycle, after Clinton served as secretary of state and has been the focus of “draft Hillary” efforts.

“Right now, we have Hillary Clinton. And that’s it,” Reid told MSNBC on Friday. “There’s not another Barack Obama out there. There are no all-stars out there. She has a clear field, and I’m glad she does.”

Clinton’s recent embrace of some more liberal positions — including on immigration policy — could make it more difficult for O’Malley to run to her left. And the presence of Sanders in the race also could complicate O’Malley’s bid to get a foothold among progressives.

O’Malley “has got to be able to squeeze himself in there somewhere,” said Kathleen Sullivan, a former chairman of the New Hampshire Democratic Party who is supporting Clinton. “He must think he has a path if he’s going to run.”

O’Malley has appeared undaunted in recent days, securing office space in Baltimore for a campaign headquarters, launching fundraising efforts, and lining up his treasurer and finance chair.

Stung by criticism that his “zero-­tolerance” policies years ago as mayor of Baltimore contributed to the unrest after the death of Freddie Gray in police custody, O’Malley has started to talk more in his public appearances about the challenges faced by cities.

On Wednesday, he told reporters that Obama and the Democrats in Congress did not do enough to help urban areas emerge from the 2008 recession, leaving “whole swaths of Americans, particularly in American cities . . . worse off than they were eight years ago.”

When O’Malley tries to plot a path to the nomination, he said he thinks about the 1984 presidential campaign of Gary Hart, where he was introduced to politics as a 20-year-old campaign worker.

Hart started out as a huge underdog against former vice president Walter Mondale. He exceeded expectations in Iowa, then won New Hampshire and gave Mondale a scare for the nomination as the race unfolded.

“Front-runners are inevitable right up until they’re not inevitable,” O’Malley said in a recent interview. “The unknown candidate today can become very, very well-known tomorrow.”

A Bloomberg-Saint Anselm poll this month showed that Clinton was the first choice of 62 percent of likely Democratic voters in New Hampshire. She was followed by Sanders with 18 percent, Vice President Biden — who hasn’t said he’s running — with 5 percent, O’Malley with 3 percent, and Chafee and Webb with 1  percent apiece.

Dan O’Neil, a Manchester alderman who led O’Malley around the diner here, said the coming months will be pivotal for O’Malley. His trips to New Hampshire over the past two years have focused on campaigning for local and state candidates, rather than selling himself.

“The political people know who he is,” said O’Neil, who considers himself an O’Malley supporter. “Now he’s got to get out and meet the voters. I think once people get a chance to meet him, they’ll give him a strong look.”

At a house party in Durham later that day, O’Malley gave a short talk in which he decried stagnant wages and the country’s growing wealth gap. He called the Baltimore riots and subsequent state of emergency “one of the most heartbreaking weeks we’ve had in a long time.”

When O’Malley started taking questions, a woman asked why she should consider him instead of Clinton.

“The ‘distinct-from-Hillary’ question,” O’Malley quipped, to some laughter. He cited his executive experience as a mayor and governor and said he has “a track record of getting things done and being ahead of the curve.”

“I see things in a way that are much more in tune with where our country is going,” said O’Malley, who is 15 years younger than Clinton, “rather than with where our country has come from.”

Wendy Alley, a former chairwoman of the Dover Democratic Committee, said she has become a fan of O’Malley after seeing him a few times but is having a hard time spreading the word.

“I keep talking him up, and some people are like, ‘Who?’ ” Alley said. “There are almost two challenges for him: getting people to know him, and then getting people to realize he’s the better choice.”

Dick Harpootlian, a former Democratic Party chairman in South Carolina, another early nominating state, said he thinks that a strong challenger could make headway against Clinton, but he doesn’t know whether O’Malley is that candidate.

“Hillary is running a humdrum campaign,” said Harpootlian, adding that he’d like to see Biden run. “If O’Malley can step up the game on an emotional level and excite people, there’s a path — but a very narrow path.”