Former Maryland governor Martin O'Malley officially kicked off his 2016 presidential campaign in Baltimore on Saturday morning, offering himself to Democrats as a younger and more progressive alternative to front-runner Hillary Clinton. (AP)

“I’m drawn to tough challenges,” Martin O’Malley said, “and this one is certainly a tough challenge.”

Unruffled in a crisp white shirt and necktie, O’Malley sat in a windowless conference room in his bustling campaign office on Friday afternoon. He was less than 24 hours away from formally launching his candidacy for president in 2016. If anything, he understated the obstacles on the road ahead.

O’Malley is running against the most formidable front-runner the Democrats have seen in many years. Hillary Rodham Clinton towers over the field of candidates for her party’s nomination, and is able to amass resources, talent, political support, volunteers and attention (for good or ill) unmatched by her challengers.

O’Malley, among others, will test whether Democrats who say they want a competitive contest for the nomination really mean it. At Clinton’s headquarters in Brooklyn, her senior advisers anticipate and are preparing for that possibility. But in the face of daunting odds, O’Malley must find the ground on which to fight.

Will he try to make the contest primarily an ideological battle, tapping progressive unrest with the state of the Democratic Party and possibly Clinton to frame a left vs. centrist contest? Will he, as his mentor Gary Hart did when the former senator from Colorado nearly upset Walter F. Mondale in the 1984 Democratic contest, seek to draw a sharp generational contrast, of future versus past, new ideas against a tired Democratic status quo? Or can O’Malley make it a combination of the two?

O’Malley said his travels around the country over the past 18 months have led him to conclude that there is “a tremendous hunger . . . for leaders who are willing to embrace new approaches, to break with the orthodoxy of some of the worn-out thinking of our past.”

But exactly what is that orthodoxy with which he seeks to break? How much is it the policies of the current Democratic administration, rather than just the Republican economic policies that he and all other Democrats attack? And how explicitly will he be able to show that Clinton embodies that orthodoxy and that he does not?

When I asked O’Malley to describe the choice he wants to put before Democratic voters in the coming months, he offered the thematic underpinning of his candidacy: “I believe the choice we have before us is new leadership for these new and changing times and challenges that we have in our country.”

On Saturday, in his announcement speech, he sought to tap frustrations about a possible 2016 general election between Clinton and GOP candidate Jeb Bush. “The presidency is not a crown to be passed back and forth . . . between two royal families,” he said. “It is a sacred trust to be earned from the people of the United States.”

Eight years ago, however, O’Malley was a Clinton supporter when she ran against then-Sen. Barack Obama for the Democratic nomination. “I supported Secretary Clinton in 2008 because I believed that she was the best candidate for those times,” he said. “I have come to the conclusion that what our country wants for the challenges, tremendous challenges we face right now, is new leadership.”

He has spent months seeking to carve out space to Clinton’s left, offering a populist message attacking big banks and corporations, decrying the wealth gap, calling for a higher minimum wage and more rights for workers and parting company with President Obama — and implicitly with Clinton — on an Asian trade pact.

Former Maryland Gov. Martin O'Malley is a Democratic contender for the White House in 2016. Here's his take on gay marriage, income inequality and more, in his own words. (Julie Percha/The Washington Post)

O’Malley sees her, though without saying so directly, as too cozy with Wall Street and big money and unwilling to get tough with those he says helped wreck the economy in 2008. “Wall Street will not police itself,” he said. “We need our federal government to do what people expected us to do when they voted for us eight years ago, and that is to take on Wall Street.”

He sees Obama as captured by corporate interests, as well, at least on the issue of trade. “I think he has probably been persuaded by all those captains of industry and corporations who stand to benefit most, who are the only ones that have been engaged in these negotiations,” O’Malley said.

But Sen. Bernie Sanders (I-Vt.) is drawing big crowds with the same message, delivered with considerable passion, aimed at those same progressive Democrats that O’Malley needs. At this point, O’Malley does not have a clear path against Clinton. Before he can get to her, he must first deal with Sanders.

O’Malley compiled a record of progressive achievement as governor. He readily cites a series of statistics and successes, from raising the minimum wage to the passage of marriage equality to higher spending on schools, to job growth better than in Virginia or Pennsylvania (though not better than states like Ohio, Michigan, Illinois or Wisconsin).

But O’Malley’s tenure in Annapolis was diminished last November when Maryland voters picked Republican Larry Hogan as his successor over his lieutenant governor, Anthony Brown. Hogan won in part because enough Democrats, unhappy with O’Malley and with the higher taxes he advocated, defected and backed Hogan.

O’Malley said his record was “undefended” in that 2014 election, “a tactical decision . . . which I’m not really in a position to second-guess. . . . You can’t blame people for making bad decisions if you don’t put the truth before them and make the arguments and present the facts.” He will make the case for himself vigorously in the presidential campaign.

More recently, O’Malley also has seen his time as mayor of Baltimore come under attack in the aftermath of the rioting that followed the death of Freddie Gray that has resulted in the indictments of six police officers. The rioting has drawn criticism of the anti-crime policies he instituted and focused attention on conditions in the poorest neighborhoods of a city he sought to turn around as mayor.

He has taken that moment as an opportunity to speak about urban problems, saying unemployment in some big cities today is higher than it was before the economic collapse. He calls for a national urban policy, something that Democratic presidential candidates long have avoided, fearing it would stamp them as the party of minorities and the poor.

Despite all these challenges, O’Malley draws hope from knowing that no nomination contest ever plays out exactly as it is scripted a year in advance. Clinton, for all her advantages, is not a candidate without flaws and vulnerabilities.

Three decades ago, O’Malley was a young volunteer in Hart’s campaign. That campaign, though the candidate ultimately fell short, animates O’Malley’s thinking. Hart lingered in single digits throughout much of 1983, only to catch fire and upset Mondale in the New Hampshire primary, setting up a long struggle for the nomination.

O’Malley said he sees parallels between then and now. “I think in our own party there is a desire for a new generation of leadership that’s more connected to the values of our country and where we’re headed,” he said.

Like Hart then, O’Malley will burrow into Iowa and New Hampshire and count on the voters there. “They’re not intimidated by big money or punditry or polls,” O’Malley said. “They’ve seen 1 or 2 percent candidates before become very well known once they make their case. And that’s what I believe we’re going to see in this race, as well.”