Hang On, Where's Elizabeth Warren At This Rally?

On Monday night, former Secretary of State Hillary Clinton was joined onstage by nearly every female Democratic U.S. Senator, many of them her former colleagues, in an attempt unite women around her candidacy. Noticeably, the arguably most famous of them didn't show. That would be Elizabeth Warren, the senior Senator from Massachusetts. She was a no-show, and no explanation was given as to why Warren skipped the Clinton rally.

Warren hasn't yet endorsed a candidate in the Democratic primary. She did sign a letter urging Clinton to run back in 2013, but later told CNN that it wasn't meant to be an endorsement. Progressive organizers from groups like MoveOn.com had encouraged Warren to run herself, a possibility she finally declined in March. Since then she has spoken positively about Bernie Sanders' policy positions but has refrained from endorsing the Vermont senator.

Clinton didn't mention Warren on Monday. She spoke solely about the prospects to take the presidency and regain control of the Senate. "We are going to do everything we can to put our country on the right track," Clinton said. "And I am hoping that because of the election next year, this time we will be able to celebrate more Democratic senators and maybe even taking the majority of the Senate back."

All the senators at the event — among them Senators Kirsten Gillibrand of New York, Barbara Boxer of California, and Tammy Baldwin of Wisconsin — spoke on Clinton's behalf. Senator Heidi Heitkamp of North Dakota called Clinton the "single most qualified, by far, of any person in this race for president." A whole 38 of 46 Democratic senators, including all the senators at the event, have already endorsed Clinton.

Gillibrand didn't acknowledge Warren's absence in her speech. "It's an honor to be here with all of my Senate female colleagues," she said. Others referenced the letter that all female senators had signed in stressing their united front behind Clinton. Fellow Senator Barbara Mikulski of Maryland said after the event that perhaps Warren had a cold.

Warren has bashed some of Clinton's policy views — although she refrains from naming Clinton. Most recently at a book release event in October, Warren said she was disappointed to see that not all Democrats agreed on the need to reintroduce the Glass-Steagall Act. The law used to separate retail from investment banking and some argue its repeal led to the financial crisis of 2008.

The two used to also disagree over the Trans-Pacific Partnership trade deal and potentially Keystone XL. Clinton took her time coming out against the pipeline. Now that she firmly opposes both, perhaps Warren will come around. Or maybe Warren thinks she can be more influential withholding her support until Clinton moves even further to the left on economic issues.

Either way, there's no doubt Warren will support Clinton in the general election if she clinches the nomination. Then we can expect a full stage of Democratic Senators, urging women to vote Clinton. After all, as Gillibrand said at the rally, "When women vote, women win."