In this photo taken Oct. 6, 2015, Sen. Elizabeth Warren, D-Mass. speaks on Capitol Hill in Washington. Warren has taken to Twitter again to bash Donald Trump, the latest in a series of Internet "tweetstorms" calling Trump on the carpet for his treatment of women and his insults toward her. (AP Photo/Jacquelyn Martin)
In this photo taken Oct. 6, 2015, Sen. Elizabeth Warren, D-Mass. speaks on Capitol Hill in Washington. Warren has taken to Twitter again to bash Donald Trump, the latest in a series of Internet "tweetstorms" calling Trump on the carpet for his treatment of women and his insults toward her. (AP Photo/Jacquelyn Martin) Credit: Jacquelyn Martin

WASHINGTON — As the rift between Sen. Bernie Sanders’ supporters and Hillary Clinton’s expands into anger and even some violent threats, many Democrats are pointing to a potential bridge: Sen. Elizabeth Warren.

The Massachusetts senator is one of the few figures in the Democratic Party who carries as much credibility with the party’s restive left wing as Sanders, the Vermont independent.

But as Democrats ask if Warren can help corral Sanders’ backers, a second question emerges: What does Warren want?

The endgame of the Democratic primaries will shape the bigger contest for influence in the party over the next four years, one in which Warren and Sanders could prove to be allies — or rivals. That potential adds even more intrigue to an already fraught situation.

“Elizabeth is more focused on the day-to-day policy battles than Bernie is, but yet she will inherit, I think, the political power that Bernie woke up out in the country,” said a longtime Warren confidant who requested anonymity to discuss the sensitive intra-party struggle.

“Bernie himself will be a much more significant figure on his return to the Senate than he was this term. Assuming they’re able to work together at some level, that creates greater power,” he added.

Warren already has taken public steps to position herself as an influential player. A series of Twitter wars with Donald Trump, in which she has attacked the New York businessman as a phony populist, has enhanced her already high popularity among Democrats.

“@realDonaldTrump spews insults and lies because he can’t have an honest conversation about his dangerous vision for America,” Warren wrote during a typical exchange.

The Democratic National Committee used the tweets in a fundraising email on Wednesday, with the subject “Elizabeth Warren is in, are you?”

Warren, who carefully calculates when and how she uses her voice, declined an interview request. Clinton’s campaign did not respond to requests for comment.

Key to Warren’s power is the belief among loyalists that she cannot be co-opted. And even as she has signaled a willingness to help Clinton win the presidency, Warren’s alliance with the former secretary of state is unlikely to be permanent or easy.

“It’s no mystery that Elizabeth has skepticism about Hillary Clinton’s positions on Wall Street matters and the people who advise her on those issues,” said Dennis Kelleher, a close Warren ally since the 1990s who heads a Wall Street watchdog group called Better Markets.

“Clinton’s got an interest in bringing Warren into the fold, and Warren’s got an interest in bringing Clinton to the right place on the issues she cares about,” he added.

Minding that relationship likely will be a continuing quandary for Clinton, much as it has been for President Barack Obama.

Some Democrats are urging Clinton to ask Warren to be her running mate _ a scenario that several senior Democrats see as unlikely to suit either of them.

“Elizabeth is someone who’s used to challenging and prodding the establishment, not speaking for it,” said David Axelrod, the former strategist and senior White House aide to Obama.

“Vice president is a job that requires you to speak for the administration, and I’m not sure she’d want to speak for an administration that she’s not leading.”

More likely, Clinton will have to decide how much informal influence to give Warren in crafting policy in her campaign and, potentially, her administration.