On the chilly morning after her election to the U.S. Senate, Elizabeth Warren greeted ecstatic commuters and faced the next inevitable question.

How would the new, scholarly heroine of the political left, who once spoke of her willingness to leave “blood and teeth on the floor” in her fight for consumer protection, position herself at a moment when American politics demands both an unyielding brawler and bipartisan compromise?

Warren’s first post-election answer left plenty of room for speculation. “I will work with anyone who’s out there to fight for America’s working families,” she told reporters before retreating home to sleep.

“Democrat, Republican, independent, Libertarian, contrarian — it doesn’t matter.”

Among the models for how Warren might approach her role as a senator from Massachusetts, the one most often mentioned is that of the state’s late liberal icon, Edward M. Kennedy. He was a reliable voice for the left who also got things done, partnering, for instance, with George W. Bush on the No Child Left Behind Act and Sen. John McCain (R-Ariz.) on immigration policy.

And there is the model offered by Hillary Rodham Clinton, who had even more star power than Warren and was, at first, viewed with suspicion by many of the GOP senators she eventually won over with dogged hard work.

There is another possibility, too, which is that Warren — a distinctive, quasi-populist figure at a transitional moment in politics — might forge a different path altogether.

“I wouldn’t point to any former senator as the model for what she does,” said Adam Green, co-founder of the Progressive Change Campaign Committee, which launched the Draft Warren campaign in July 2011 to persuade her to run. “She is Elizabeth Warren.”

What is certain is that among new lawmakers heading to Washington in January, few carry the particular kind of popularity, hope and sheer expertise that the folksy Harvard law professor does. The question is how she will express her fiery progressivism in the deliberative body, where deference and seniority are often prized more than bravado.

There is also the question of her relationship with the White House — whether she will follow President Obama’s lead or try to nudge him to the left — and with a Democratic Party often accused of lacking spine.

“I don’t think she will disappoint anyone,” said Sen. Al Franken (D-Minn.), speculating sarcastically about the expectations Warren faces. “There will be not one single person disappointed by anything she does or anything she says. Not one.”

‘People-powered candidate’

Once an obscure academic studying bankruptcy law, Warren did not court the spotlight so much as the spotlight courted her — first as one of the nation’s preeminent chroniclers of middle-class decline and then as the outspoken head of a congressional panel established to oversee the 2008 Wall Street bailout. She perhaps gained the most notoriety when she set up the Consumer Financial Protection Bureau.

With her rolled-up blazer sleeves and wire-rimmed glasses, she was loved and reviled as the wonky, self-described champion of consumers against big-bank interests, often saying that as a tenured Harvard professor, she had little to lose by sticking her neck out.

As she campaigned for Senate, Warren remained bold, saying she would not shy from raising taxes on the wealthy or cutting the military budget to pay for education, deficit reduction and other priorities.

She also injected fresh language into the liberal-conservative debate, saying the issue is not big vs. small government but rather whose interest government serves.

In her victory speech Tuesday night, Warren maintained a populist tone, reiterating her pledge to “hold the big guys accountable.”

And so, as Warren prepares to enter the Senate, perhaps the highest expectations come from the progressives who helped press her into the race.

“We expect her to be the same person governing that she was when campaigning,” said Green, of the Progressive Change Campaign Committee, which raised $1.1 million of Warren’s $38 million campaign haul and made nearly 600,000 phone calls to potential voters.

Pointing to her record of taking on banks, he said her election was nothing less than a “defining moment in taking on corporate power.”

Of equal importance, he said, is that Warren will think differently about how to get things done in Washington, not just relying on relationships with other lawmakers but also heading to the grass roots for support — what Green called an “inside-out” strategy.

“She understands the importance of being bold and rallying the public on the outside in order to impact change on the inside, which is a game-changing mentality to bring to the Senate,” he said. “She will show what it means to have a people-powered candidate to take on the big guys. That is our hope.”

He added, “So, no pressure.”

Defining her path

Others see Warren following a more traditional path, most likely that taken by Kennedy, who held what will be Warren’s Senate seat for decades until his death in 2009. In her victory speech, Warren said her election came almost precisely 50 years after his. “Fifty years ago, he said that he would dedicate all his strength and will to serve you in the United States Senate,” Warren said. “For 47 years, he lived up to that promise. Tonight, I pledge to do the same.”

Thomas Whalen, a professor of politics at Boston University, said Warren could do worse than to emulate Kennedy.

“He was one of the greatest in the modern political era to hammer out compromise,” Whalen said. “Kennedy always said the greatest enemy was trying to get everything done at once. Progress is about incremental change.”

Whalen also sees parallels between Warren and Clinton, who arrived with incredible prominence but very deliberately tried to play it down, relying instead on mastering the ways of the Senate, showing deference to senior members and knowing the minutiae of her issues.

“Everyone said she’s going to be this partisan firebrand, but she turned out to be one of the more moderate members,” Whalen said.

Rep. Barney Frank (D-Mass.), who worked with Warren when she headed the panel overseeing the bank bailout and when she was setting up the consumer protection bureau, said Warren has been on the inside, in a sense, and showed a willingness to compromise when necessary.

“She isn’t just parachuting in. She played a major role in financial reform,” said Frank, who is retiring from the House.

He added: “She is a very effective advocate. She understands avoiding the danger of giving away too much or being so rigid that you don’t get anything.”

Franken, who hosted Warren on his radio show before she became widely known, said she will have to balance the instinct to jump in against the need for a period of learning the ropes.

He said Warren’s deep knowledge of middle-class economics is likely to put her in high demand among Senate colleagues. “She has an area of expertise, which is very, very important right now,” he said, referring to Warren’s work on how health-care costs, credit-card company rules, predatory lending and other features of the American economy squeeze working families. “She’ll have a role as the go-to person on issues like that.”