Last night, Hillary Clinton narrowly defeated Bernie Sanders in the Massachusetts primary. According to the A.P., the final tally was 50.3 percent to 48.5 percent—with more than 1.1 million votes cast, Clinton’s margin of victory was 20,000 votes.

There’s an argument to be made that it was her most important win of the night. Eleven states held Democratic primaries or caucuses on Super Tuesday, and the schedule was heavily stacked in favor of the southeast. Six of the 11 contests were held in “SEC country,” and Clinton’s dominance in the southern black demographic meant she was going to score huge wins in all of them. Of the remaining five states, Sanders won four—Oklahoma, Colorado, Minnesota, and his home state of Vermont. If he had also won Massachusetts, he could have made a powerful claim that despite Clinton’s delegate lead, he was the one winning the blue states and swing states that will matter so much in the general election. Clinton’s victory in Massachusetts tempers that argument—it’s her first win in the northeast, and by planting a flag in Sanders’ backyard, she landed her biggest symbolic body blow of the night.

Elizabeth Warren is the senior U.S. Senator from Massachusetts, and prior to taking office in 2013, she was a lawyer who frequently advised Congress and chaired the Congressional Oversight Panel after the economic crash of 2008. She’s an icon among progressives, and the “Draft Warren” movement was a serious effort to get her to run for president as an alternative to the significantly more conservative Hillary Clinton. When she opted not to run, Bernie Sanders filled that progressive void, and her constituency threw its weight behind the Senator from Vermont.

There will be very few absolute statements in this article, but there is one thing that I think we can declare without hesitation: If Warren had endorsed Sanders at a reasonable date before the Massachusetts primary, and spent the run-up campaigning for him and appearing at his rallies, Bernie Sanders would have won the state. I don’t think there’s much reasonable doubt there, especially when you consider the narrow final margin. Warren is beloved in her state, and by Democrats and progressives in general, and her influence is easily worth 20,000 votes. In that sense, she cost Sanders an important win.

Warren hasn’t endorsed either candidate, and politically, that’s probably a smart move. But who would she choose if there were no secondary considerations, and she could express her support without consequence?

She won’t comment on that preference publicly, but there have been enough hints for us to make a reasonable guess—not the least of which is the absence of an endorsement for Hillary, which makes her unique among the 14 female Democrats in the Senate.

The best argument that she supports Clinton comes from a letter written by Barbara Boxer in early 2013 in which she urged Hillary to run. That letter was signed by every female Senator, including Warren. Here’s what Boxer had to say on MSNBC:

SEN. BARBARA BOXER: Well, this is what I want to tell you. A couple of years ago, I organized a letter, every single Democratic female senator signed it, including Senator Warren. And it was urging Hillary to run. Urging her to run. Hillary is very thrilled that we all signed it. I think Elizabeth has her issues, and this is up to her. But I think people are really gravitating toward Hillary Clinton right now.

As far as evidence goes, that’s pretty tepid—it was a private letter long before the election, and nobody knew Bernie Sanders would mount a serious challenge three years later. Even while bringing it up, Boxer couldn’t avoid the reality of Warren’s “issues.”

So what about the argument for Sanders? Well, here you can simply point to the bulk of Warren’s career, where she has routinely come down on the side of progressive causes, particularly on the economic front. But the truth is, we don’t even need to delve deep into her political past to know that she has serious objections to Hillary’s conservative economic approach. In an interview with Bill Moyers from 2004, she details exactly how Clinton let her down on bankruptcy legislation, and extrapolated from there to a larger point about the systemic corruption in American politics. In that anecdote, Clinton was the poster child for the routine sell-outs happening in D.C.:

More recently, just days before the Iowa caucuses, Warren took an indirect-but-still-pretty-direct shot at Clinton after a January debate in which Clinton told voters that universal health care was too difficult to be worth the effort:

"Anyone who shrugs and claims that change is just too hard, has crawled into bed with the billionaires." @SenWarrenpic.twitter.com/VB1Z13PH4a — Josh Smith (@joshsmith) January 22, 2016

She also skipped a fundraiser in December that was attended by each of the other 13 female Democratic Senators, and has spoken positively about Sanders, saying, “Bernie is doing what Bernie always does — he's out there talking from the heart, raising the issues that he's raised for decades now,” said Warren. “That's just who he is.”

And when Goldman Sachs CEO Lloyd Blankfein said that Sanders' Wall Street criticism had created a “dangerous environment,” Warren struck back with a rousing defense:

“He thinks it's fine to prosecute small business owners, it's fine to go hard after individuals who have no real resources, but don't criticize companies like Goldman Sachs and their very, very important CEO — that's what he's really saying.

The evidence doesn't stop there, but you get the point—it's overwhelming. From a political and philosophical standpoint, it's clear she aligns far more closely with Bernie Sanders than Hillary Clinton.

But that's not the same as an endorsement. Not even close.

Tulsi Gabbard, a Samoan-American congresswoman from Hawaii and a combat veteran who served in Iraq, quit her post as vice chair of the Democratic National Committee on Sunday over objections that the organization was stacking the deck for Hillary Clinton. She endorsed Sanders on the basis that Clinton has shown a willingness to draw America into disastrous wars in the Middle East—wars which she experienced firsthand—and Sanders would exercise more “sound judgment.”

“I cannot remain neutral any longer,” she said in a video announcement. “The stakes are just too high.”

It's a principled stand, especially at a time when most analysts believe that Clinton will win the nomination. And it will come with serious consequences—the Clintons are notoriously brutal on Democrats who break ranks, and in an interview with Brian Williams on MSNBC, Gabbard spoke about the warnings she received from fellow politicians (3:45 mark):

“I'll be very honest with you,” she said, “a lot of people warned me against doing what I did. But this is a very serious issue, and what I did speaks to the high stakes that exist.”

That's one approach to take, and as much as you might admire Gabbard, you have to understand that she may have just committed political suicide. Warren, who holds a place of esteem in the Senate, had opted for a different strategy. We can't see inside her head to know every detail, but a Politico piece that ran Monday, using sources close to Warren, gives us the clearest idea yet on how she's using her endorsement to consolidate and increase that power. Essentially, she seems to be holding out long enough to use her progressive bona fides as a bargaining chip—trading her cachet for power, with the goal of bringing the Sanders constituency back to Clinton for the general election at a time when many have vowed to stay at home.

If Clinton wins enough delegates by the end of March to become the presumptive Democratic nominee, Warren is expected to negotiate hard before giving her support to Clinton. In doing so, she could play a critical role helping to bring young, enthusiastic Sanders supporters into her fold.

Meanwhile, there was a sort of tacit truce at play in the state, with unspoken but serious terms: Hillary would keep the lines of communication open, and Warren wouldn't be punished with that famous Clinton vengefulness as long as she didn't endorse Sanders outright.

In politics, there are always calculations to be made. It's safe to say that Warren doesn't believe, in her heart of hearts, that Bernie Sanders has a chance to defeat Hillary Clinton and win the presidency. Therefore, alienating Clinton by endorsing her rival would only serve to diminish her own influence in the Senate, and by extension the whole progressive cause, with no tangible benefit. Instead, she's play the middle road—not exactly backing Clinton, but staying close enough to avoid incurring her wrath, and in the process increasing her own value as one of the few Democrats who can credibly reach out to the progressive base on Clinton's behalf in November.

The day after Sanders' Massachusetts loss, there are plenty of understandable frustrations with Warren's tactic. But it's important, in the midst of the disappointment, to understand that politics is a long game, and Warren's approach isn't just about self-preservation—there's wisdom there too.

Let's be fair to both sides here. Warren wasn't wrong to play the system, but nor are Sanders supporters wrong to feel that in a critical moment—with an actual, real-life progressive fighting against Clinton—Warren let them down. There's an incredible amount of passion behind Sanders, and among his core supporters, Warren approaches hero status. She's one of the few members of Congress who routinely fights for progressive causes with passion and a razor-like intelligence, and for many, she was the first choice for the role Sanders now occupies. In a system controlled by big money and corporate interests, she stood out for reliably fighting against the juggernaut. This time—facts are facts—she remained on the sideline.

So, sure, Sanders supporters have a right to be upset, and they have a right to be vocal. Predictably, they took to social media express this discontent, and even more predictably, Clinton supporters immediately tried to turn it into something sexist—that's pretty much their modus operandi. Before long, tweets like this one had begun to make the rounds:

At the link in question, there were 9,000 comments total when Brownworth posted, which means that for her claim to be true, all 9,000 would have to have been “threats.” Last night, I sorted for the top comments, and took a screen shot of the “threats”:

Those comments are intense, and impassioned, but they are not threats. Some of them are downright respectful, and the angry ones are only raising political points. For someone like Brownworth to use the word “threats” is the kind of deeply dishonest tactic that seems designed to divide the Democratic party along ideological lines and ensure that there will be no happy reunion after the nomination process.

Just now, to make sure I wasn’t missing anything, I sorted by recent comments to see what was happening on that same post. The results:

Again, that’s a lot of righteous anger. You might disagree with the logic behind some or all of the statements. But the words come from politically motivated Americans of both genders, and none of it falls to the level of harassment. Here’s some more, using the “previous comments” button just above the “most recent” batch:

Again, nothing even approaching a “threat.” In fact, I haven’t seen even one example of sexism or harassment. I certainly have scrolled through thousands of comments, but I’ve seen enough to know that if they exist, they’re unfortunate outliers, and not representative of the general tone, which is best described as “disappointed” or “outraged.”

Nevertheless, there’s a budding movement to scold Sanders supporters for making their views public. It’s almost as if the mere fact of their passion is offensive, and it’s nothing for people like Brownworth—and so many others—to treat that passion as though it were actual offensive content.

But these are not threats. You know what they are? Examples of democracy, where people have the right to express political opinions. The truth is, Sanders supporters revere Elizabeth Warren. They even love her, because they know she’s a fighter, and real fighters are in short demand. With the benefit of time, they may come to realize that she made the smart move in 2016, and actually helped the cause down the line. But for now, they’re disappointed, and this collective expression is actually beautiful, in its own way—it’s a sign that people care, and that at some level in this failing country, a passion for democracy still exists.

Warren is a smart politician, and there’s wisdom in living to fight another day. I would urge all Sanders supporters to understand that. But I would urge everyone else to understand that they are not obliged to understand it. Not right now. We’re not even 24 hours past the Massachusetts loss. This is the mourning period. This is the time for people to express sadness, and surprise, and yes, even anger.

Nobody can see the future, and progressive voters have good cause to mistrust notions of intangible gains waiting somewhere down the line. What they know right now is that they fought hard, and they came up short. And they know that in the midst of their battle, when they needed a powerful ally—when it would have made all the difference—Elizabeth Warren was nowhere to be found.