Hillary Clinton (center) was joined by (from left) Barbara Boxer, Barbara Mikulski, Dianne Feinstein and Patty Murray, along with other female senators, at the Women Senators for Hillary Endorsement Dinner, Nov. 30. in Washington, D.C. | M. Scott Mahaskey Warren is missing link at Clinton's dinner with women senators Hillary wins backing of 13 of 14 Democratic women, but the most important endorser is a holdout. 
 
 Summoning 13 female Democratic senators to a high-profile fundraiser-cum-endorsement summit just a half mile from the Capitol on Monday night, Hillary Clinton’s campaign wasn’t shy in its goal of showcasing the front-runner's wide backing among the party’s leaders, and its women in particular. 
 
 But the Brooklyn-based operation knew full well that the one Democratic female senator who wasn’t there would cast a long shadow over the Hyatt Regency and the evening’s festivities: Elizabeth Warren. 
 
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 The Massachusetts progressive’s lack of a Clinton endorsement is “just not at all surprising,” in the words of one longtime Clinton loyalist and friend. But her continued absence still comes at a time when many high-level Clinton backers are growing increasingly convinced that the Bostonian's backing will be important for Clinton in energizing Bernie Sanders’ supporters and uniting Democrats during the general election. 
 
 The front-runner’s team has kept in close touch with Warren’s office throughout the seven-month campaign, said individuals close to the effort, and many top Democrats are quick to note that the candidate has kept some of Warren’s pet issues near the forefront of her campaign message. Nonetheless, that doesn’t mean anyone close to Clinton is expecting Warren’s official backing anytime soon, a handful of plugged-in fundraisers and strategists suggested — even though Warren joined her fellow female senators in signing a private letter encouraging Clinton to run back in 2013. 
 
 “Her word still goes a long way with a lot of the Democratic base. She’s still loved by many in the Democratic Party, that’s not going to change,” said strategist Maria Cardona, a 2008 Clinton campaign official. “But I wouldn’t read too much into [her reluctance to endorse]. She was also one of the original signers of that letter." 
 
 Scores of people close to Clinton pointed to that letter on Monday, and emphasized that the evening’s event was still a testament to Clinton's organization compared to Sanders’. 
 
 North Dakota Sen. Heidi Heitkamp kicked off the evening by immediately alluding to that letter, but Warren's name never came up, even if it was on many minds in the room. 
 
 Without Warren in its corner, the campaign is leaning hard into its latest political muscle-flex — unmistakably reminding Sanders supporters that nearly all his colleagues, and the bulk of the party’s establishment, are behind Clinton as the primary enters the homestretch before Iowa and New Hampshire vote. Monday’s headline-grabbing dinner and reception hosted by an array of powerbrokers, which has been hotly anticipated for weeks by elected officials and donors alike, is just the latest effort in that push. 
 
 It’s a push that all but ignores Warren’s months-long refusal to throw in her lot with either the former secretary of state or her Senate colleague Sanders, even though some of her top former staffers now work for Clinton. 
 
 The senator is widely regarded in Clinton circles as the one most important public official left to endorse the candidate outside of the White House. Warren has been active in fundraising and supporting Senate hopefuls like Kamala Harris and Russ Feingold. 
 
 But while waiting on Warren, the Clinton team has been focused on tapping the political networks of its existing supporters. 
 
 The 13 female senators in attendance on Monday night each delivered remarks in front of a crowd of roughly 1,000 before a closed dinner — which underscored the depth of Clinton’s Washington support, Sen. Kirsten Gillibrand told POLITICO ahead of the reception. 
 
 With rapid-fire speeches about Clinton’s record and the importance of women in leadership, the senators alternated between piling on the Republicans (when she reads about Donald Trump, “I say out loud, ‘He said what? He said what? Are you kidding?,” said Missouri’s Claire McCaskill) and praising the candidate (there are many reasons to support Clinton, “and most of them are substantive!” said Wisconsin’s Tammy Baldwin) while the crowd milled around the high-ceilinged basement ballroom and perused the well-stocked bars. 
 
 Heitkamp, Baldwin, Gillibrand, McCaskill, Hawaii’s Mazie Hirono, New Hampshire’s Jeanne Shaheen, Minnesota’s Amy Klobuchar, Washington’s Maria Cantwell, Michigan’s Debbie Stabenow, Washington’s Patty Murray, California’s Barbara Boxer and Dianne Feinstein, and Maryland’s Barbara Mikulski each riled up the room with no nods to Warren and few acknowledgements of Clinton’s primary rivals, aiming to energize one of the campaign’s largest fundraiser crowds yet. 
 
 By the time Shaheen had promised a victory in New Hampshire and Klobuchar had predicted a win in Iowa, the crowd was ready for Clinton, who came on stage and immediately hugged each senator. 
 
 “If you’re ready for me, I’m ready for you,” she said with a smile. 
 
 Such a show of force before Clinton then delivered a version of her standard stump speech was a reminder of the historic nature of Clinton's candidacy, said former Michigan Gov. Jennifer Granholm — a point the campaign may soon start making more forcefully. 
 
 “We’ve never seen such a consolidation of support behind one individual candidate on the part of elected women,” Granholm said. “Endorsements matter among the get-out-the-vote workers. While there’s an argument out there about how much value endorsements have, if it seems like there’s a bandwagon effect, the voters go along. And the people on the ground who are involved with getting people out to vote are enlisted much more easily. So these sorts of endorsements matter." 
 
 Just six Democratic senators have yet to formally endorse Clinton, while none have backed Sanders. The campaign invited each of the female senators individually, their offices said, and each brought along a distinct message Monday in support of the front-runner. 
 
 
 
 “It shows the breadth of her support and the diversity of her support. We all come from very different states and represent very different constituencies,” explained Gillibrand of the message sent by Clinton’s Senate supporters, particularly from the chamber’s women. 
 
 Like Granholm, who is involved with pro-Clinton super PAC Correct the Record, Gillibrand is an active campaign surrogate, having already campaigned for the candidate in Ohio, and planning trips to New Hampshire and Iowa. 
 
 With that kind of surrogate work becoming an increasing focus, some Clinton donors are increasingly grumbling that Warren is losing some of the political leverage she once had by holding out for so long. 
 
 So as the Iowa caucuses approach and more voters tune in, many said, Warren’s endorsement is regarded as more and more likely. 
 
 “Certainly she’s got the right, like all Americans, to make up her mind on her own time frame, but her values and her vision is similar to Hillary Clinton’s,” said Granholm. 
 
 “She’ll make up her mind in her own time. I’d be surprised if she didn’t sign on eventually." 

 One by one tonight, 13 female Democratic senators took the stage inside the packed ballroom at the Hyatt Regency in Washington, DC to raise money and announce their support for Hillary Clinton. 
 
 But it was the person missing from the group who stood out most. 
 
 Elizabeth Warren, the progressive lawmaker from Massachusetts, was the only female Democratic senator who wasn't at the endorsement event and fundraiser for Clinton's presidential campaign. 
 
 Warren, who many thought would run for president herself, has so far declined to back anyone in the primary. She is also one of only six Democratic senators who has not endorsed Clinton. 
 
 Clinton's campaign said it invited the 13 female senators who have endorsed Clinton to attend tonight's event, but would not say whether or not they invited Warren. They also would not comment about Warren's absence. 
 
 "We're honored to have 13 women Senators coming together to endorse and support Hillary Clinton," Clinton spokeswoman Christina Reynolds said in a statement, "This is a sign of the broad support Clinton is receiving from women across the country who know she'll fight for us." 
 
 Warren's senate office declined to comment. 
 
 Last year, all of the female Democratic senators -- including Warren -- signed a secret letter to Clinton encouraging her to run for president. Warren later clarified that while she supports Clinton running, she had not endorsed her. 
 
 "You know, all of the women -- Democratic women, I should say, of the Senate -- urged Hillary Clinton to run, and I hope she does," Warren told ABC News' George Stephanopoulos last year when asked if she would back Clinton. 
 
 "Hillary is terrific," she replied when asked again. 
 
 Many of the other senators who signed that letter were at the event tonight, including Senators Tammy Baldwin, Barbara Boxer, Maria Cantwell, Dianne Feinstein, Kirsten Gillibrand, Heidi Heitkamp, Mazie Hirono, Amy Klobuchar, Claire McCaskill, Barbara Mikulski, Patty Murray, Jeanne Shaheen and Debbie Stabenow. 
 
 No one, however, made any mention of Warren's absence during the program. "I'm not sure why she wasn't," Mikulski said coyly, "Maybe she has a cold." 
 
 The fundraiser tonight, which was held just blocks from Capitol Hill, was only the second of Clinton's fundraisers to be open to the press. More than 1,000 people attended and tickets ranged from $250-$2,700, according to the campaign. 
 
 Clinton, who spoke following remarks from each of the Senators, spoke broadly on a range of issues such as equal pay, paid leave, marriage equality, climate change, the economy and terrorism. 
 
 She also offered her thanks and praise of her former colleagues. 
 
 "They have so much courage and smarts, the combination of grit and grace," Clinton, a former senator, said pointing to the women standing on stage behind her, "It was the honor and privilege of my life to serve with them."
– Thirteen of 14 Democratic female senators showed up Monday night at the DC Hyatt Regency for what Politico calls a "high-profile fundraiser-cum-endorsement summit" for Hillary Clinton, but it was the absent No. 14 who caused the most buzz. Sen. Elizabeth Warren still hasn't thrown her weight behind any one candidate and is one of only six Democratic senators who hasn't backed Clinton, ABC News reports. What's still a mystery is whether the Massachusetts senator opted on her own not to attend the fundraiser or if the Clinton campaign didn't invite her in the first place. Warren's office declined comment, per ABC, and a Clinton spokeswoman simply said in a statement, "We're honored to have 13 women Senators coming together to endorse and support Hillary Clinton. This is a sign of the broad support Clinton is receiving from women across the country who know she'll fight for us." Maryland Sen. Barbara Mikulski floated another theory about Warren's no-show, via ABC. "Maybe she has a cold," she says. (Maybe Clinton and Warren need another "cordial and productive" get-together.)