Elizabeth Warren may not be running, but she's in 2016 race anyway

Hillary Clinton has struck a populist tone in her early days as a presidential candidate, and at times, she sounds like liberal darling Elizabeth Warren. There's a reason for that.

Sen. Elizabeth Warren (D) of Massachusetts, darling of the liberal left, isn’t running for president in 2016. But in a way, she’s still very much in the race.

Just listen to Hillary Rodham Clinton speak in these early days of her campaign, and the populist, Warren-esque language on income inequality and social mobility is unmistakable.

Mrs. Clinton is, in her own words, a “champion” for “everyday” Americans. She speaks of how “the deck is still stacked in favor of those at the top.” She decries high-level executive pay: "There's something wrong when CEOs make 300 times more than the typical worker,” she said in an e-mail to supporters on Sunday, a line she has repeated since.

Clinton has also firmly planted a flag in cultural liberalism. In her announcement video, she included a gay couple planning their wedding, a lesbian couple, a biracial couple, and two Hispanic brothers speaking, in Spanish, about the business they’re starting.

“It’s striking that, absent serious primary competition that might have forced her left in the primaries, Hillary has gone left anyway: with culturally progressive imagery, a class-oriented economic message, and a purely domestic focus,” writes Peter Beinart in The Atlantic, noting that both Hillary and her husband, former President Bill Clinton, have spent decades occupying a more centrist Democratic space.

There are multiple reasons for Mrs. Clinton to hug the left. First, she needs Senator Warren’s supporters to get excited about her – and not just vote for her grudgingly in the general election. She needs them to donate and volunteer. If enough Warren enthusiasts sit this election out, Clinton could have a hard time winning.

Warren’s appeal stems in part from her ability to articulate the concerns and aspirations of working Americans. Though a former Harvard Law professor, she comes from humble roots in Oklahoma, the daughter of a janitor. Clinton grew up in middle-class comfort in suburban Chicago and is now quite wealthy. Warren often calls herself a “fighter” – just as Clinton is now doing.

Second among reasons for Clinton to go left: There’s always the possibility that Warren will change her mind and get into the race, especially if Clinton appears to falter seriously. The Ready for Warren draft campaign is alive and well – and still organizing. The group is about to unveil “Environmental Activists for Warren,” the latest sign that environmentalists fear that Clinton “won’t take a strong stand on the issues they care most about," National Journal reports. For starters, her stand on the Keystone XL pipeline is unclear.

Third, it may be that a “liberalizing” of the Clinton brand is the way to go in November 2016, not just the primaries.

“This is going to be a battle for the middle class,” says Democratic strategist Peter Fenn. “So I think that this is a good general election strategy, as well as a good primary strategy.”

President Obama has made the economic concerns of middle-class Americans a central theme of his second term – stagnant wages, paying for college, making health care more affordable. The economy is slowly recovering from the Great Recession, but many in the middle class still feel they’re falling behind, even if they’re employed. Clinton has already grabbed that baton and run with it, but as a wealthy woman with ties to Wall Street and decades inside the Washington power elite, she has work to do.

In addition, Clinton has other expected Democratic primary challengers to pay attention to, and probably debate. Former Maryland Gov. Martin O’Malley has been visiting early primary states and striking a populist tone. Sen. Bernard Sanders (I) of Vermont, a self-described Democratic Socialist, is moving toward a possible presidential campaign, and he may reregister as a Democrat to be eligible for debates.

Warren herself hasn’t exactly burst forth with enthusiasm for Clinton’s candidacy. Three days before the former secretary of State announced, Warren was asked on “CBS This Morning” whether Clinton is the “future of the Democratic Party.”

"Well, I think we have to see, first of all, if she declares, and what she says she wants to run on," Warren said. "I think that's really the interesting question at this point.”

Another liberal holdout on Clinton’s candidacy is Mayor Bill de Blasio (D) of New York. His hesitancy is more surprising, as he is personally close to the Clintons. In 2000, he managed Mrs. Clinton’s campaign for US senator from New York. In January 2014, Mr. Clinton officiated at Mr. de Blasio’s inauguration.

On Sunday, de Blasio told NBC that he was waiting for Mrs. Clinton to outline an “actual vision” for her candidacy.

De Blasio’s reserve may say more about him than about her. But it’s true that Clinton has yet to lay out an overarching rationale for her bid. Only this week she hired three top policy aides to help her craft a detailed agenda.

One thing is certain: Liberals are watching closely, and if they don’t like what they see, Clinton may have more to worry about than just Republicans.