Former Maryland governor Martin O'Malley (D) speaks at a presidential forum during a conference hosted by the International Association of Fire Fighters. (Alex Wong/Getty Images)

Democrats pining for an alternative to Hillary Rodham Clinton are hungry for a liberal lion, and Martin O’Malley has been doing his best to fill the role. The former Maryland governor has of late called for Wall Street reform and an expansion of Social Security benefits and touted his pro-immigrant and collective-bargaining credentials.

But on Wednesday, the 2016 presidential aspirant offered a different picture that is more uniquely him: that of a data-driven technocrat.

O’Malley addressed an audience at the staid Brookings Institution on the use of statistics to drive policy decisions and measure government performance, strategies he called “near and dear to my heart.”

It was a pivot from what many regard as the natural way to run against Clinton — from the left. And while it may be a more natural fit for O’Malley, it highlights one of his challenges in trying to position himself as the anti-Clinton candidate that many in the party are yearning for.

“I’m not sure if that will get people out of bed excited and ready to knock on doors,” said Nathan Blake, a Democratic activist in Iowa who helped host an event for O’Malley in the Des Moines area last year. He added that he is “one of those people” hoping for Sen. Elizabeth Warren (Mass.) to get into the Democratic primary as a more liberal and inspiring alternative to Clinton.

Former Maryland governor Martin O’Malley responds to a question about Hillary Clinton's private email account after giving a speech at the Brookings Institution in Washington. (Brookings Institution via YouTube)

“I like Martin O’Malley, but I’m not sure if the space is there for him,” Blake said. “He has progressive ideals, but he’s not an Elizabeth Warren. It’s a different sort of leadership.”

O’Malley aides argue that his progressive stances and his “new way of governing” are two sides of the same coin. He is a governor with a solidly progressive record on a range of issues, they say, and he also knows how to run a government. Unlike some starry-eyed liberals, they suggest, O’Malley can actually get things done.

As if to prove the double-edged point, O’Malley on Tuesday hewed more closely to the liberal script that is exciting Democratic activists looking for an alternative to Clinton. The former secretary of state is eyed with some suspicion from the left for, among other things, her close ties to Wall Street, her more hawkish views on foreign policy and her onetime opposition to allowing undocumented immigrants to obtain driver licenses.

“The American Dream will never die on our watch, because we choose to fight, and we intend to win,” O’Malley said at a forum in Washington sponsored by the International Association of Fire Fighters. “That means raising the minimum wage, expanding eligibility for overtime pay and respecting the rights of all workers to organize. To make the dream true again, we must expand — and not reduce — Social Security benefits.

On Wednesday, O’Malley’s message tilted to the wonkier side.

He relayed how, as mayor of Baltimore in 2000, he pioneered a program called CitiStat that used data to hold agency heads accountable for how quickly potholes were filled, how often trash pickups were missed and how often their employees were skipping work.

When he became governor in 2007, O’Malley took the program statewide. Before long, he was using measurements to take on new tasks, including cleaning the Chesapeake Bay, curbing infant mortality and increasing transit ridership.

On Wednesday, he said that he sees a role for the program on the federal level.

“There’s not a doubt in my mind that this is the new way of governing and getting things done,” he said. “This is the way our federal government should operate. . . . The larger the human organization, the more important performance-based measurement becomes.

For instance, if the United States reduced infant mortality at the same rate Maryland has, 4,000 American babies a year would survive, he said.

Over the course of nearly an hour, in front of a politely attentive audience, he talked about using numbers to shape initiatives on everything from keeping people from returning to prison to boosting the number of oysters in the Chesapeake Bay.

During a question-and-answer session, O’Malley fielded a few wonkish questions from good-government types in attendance. Most of the queries from the news media focused on Clinton’s use of a personal e-mail server while she was secretary of state.

The concept of data-driven government originated with policing efforts in New York, but O’Malley became the first to expand it across a full government.

“He was the first guy to figure out how to make it work for an entire jurisdiction,” said Robert Behn, a senior lecturer at the Kennedy School at Harvard University who has written extensively about government leadership strategy.

In Baltimore, agency heads were summoned to the CitiStat room on the sixth floor of City Hall every two weeks to explain statistical trends to the mayor and senior members of his staff.

Matthew Gallagher, who was the program’s director and later became O’Malley’s chief of staff in Annapolis, said CitiStat became a “fundamental bedrock” of O’Malley’s governing philosophy, adding, “It’s something he’s rightfully proud of.”

Data was collected and analyzed to help deploy police resources in the fight against violent crime. It was employed to make good on O’Malley’s pledge to fill potholes within 48 hours. And it helped guide efforts to combat graffiti in business corridors.

Buzz about the program brought “literally thousands” of visitors to Baltimore from around the globe who were seeking to replicate it for their governments, Gallagher said. As many Republicans as Democrats were interested. One month, representatives of 11 countries sat in on CitiStat sessions. O’Malley’s staffers maintained a map with pushpins showing the far-flung interest.

As technology evolved, his staffers developed more uses for the data, including publicly accessible charts, tables and maps showing various trends. At one point, the program landed on the cover of Governing magazine.

If O’Malley’s passion lies in data, he has also grown more comfortable in recent months talking about liberal causes.

In New Hampshire last week, he called for reinstating the Glass-Steagall Act, the Depression-era measure that separated commercial and investment banking. Warren, who has said she is not running for president, has argued that the act’s repeal in 1999 under President Bill Clinton contributed to the 2008 global credit crisis.

And O’Malley regularly boasts of a string of progressive legislative victories in Maryland, including the legalization of same-sex marriage, repeal of the death penalty, enactment of sweeping gun-control measures and an increase in the minimum wage.

But O’Malley was not always the first to join the fight — and has never been a liberal crusader, according to Maryland lawmakers.

For instance, he sponsored the 2012 bill that legalized same-sex marriage, but he did not come on board until a similar measure unexpectedly fell just short the year before and advocates appealed for his help. Before that, O’Malley had a long history of advocating for civil unions as an alternative to same-sex marriage.

Likewise, he pushed the gun-control bill through the legislature in 2013 in the wake of the school shooting in Newtown, Conn. Before that tragedy, however, O’Malley had not embraced the perennial efforts of lawmakers who sought to put tighter restrictions in place.

“It was a couple of years before he got involved,” said state Sen. Paul G. Pinsky (D-Prince George’s), one of the chamber’s more liberal members. “But he brought those issues across the finish line, and he brought some reticent Democrats along.”

State Sen. Jamie B. Raskin (D-Montgomery), a self-described fan of O’Malley who hasn’t picked sides in the presidential race, said being so steeped in data can have a down side.

“He can sound like a techno-wonk,” Raskin said.

O’Malley, who plays in a semi-retired Celtic rock band, would be better off if he invoked the social justice passions of a fellow musician, Raskin said. “I’ve told him he needs to release his inner Bruce Springsteen if he’s going to do this.”