Late Friday afternoon, a press statement appeared on the website of the think tank Demos that set significant segments of policy Twitter and left-wing political Twitter ablaze. They said they had, in essence, fired Matt Bruenig from a part-time job blogging on their website over his refusal to apologize for a couple of mean tweets he'd directed at Neera Tanden, the head of a rival think tank, the Center for American Progress.

Disagree w/ him often & he has unfortunate mean streak, but @MattBruenig is worth reading & an interesting thinker. He'll find a good home — Modeled Behavior (@ModeledBehavior) May 20, 2016

On one level, this Bruenighazi is exactly what it seems to be: a matter of considerable importance to one family's finances but essentially a tempest in a teapot — a series of personal spats boiling out of control.

This seems a good a time to point out that demands for civility are most often the ruling class demanding fealty https://t.co/D4dscJRIgW — Amber A'Lee Frost (@AmberALeeFrost) May 20, 2016

But to many, it reflects something larger, the latest in a series of efforts by the forces of centrist liberalism to stifle more left-wing voices in order to serve the interests of capitalism. Or, at minimum, the latest in a series of moves by allies of Hillary Clinton to keep Bernie Sanders's political revolution down.

A social democratic tsunami is headed for the @thedemocrats. May it smash their party to pieces or at least wash away the scum at the helm. — Connor Kilpatrick (@ckilpatrick) May 20, 2016

And behind this fight lurks two broader, and perhaps more consequential, trends in political debate: the Democratic Party's evolution on welfare reform, and the broad and persistent harassment of women and people of color on Twitter.

Catch me up — who are these people, and what happened?

The key players in the drama are:

Matt Bruenig, a young attorney who's much better known for his side career as a data-oriented left-wing writer and for what I guess you would call his side side career as an aggressive left-wing Twitter personality

side career as an aggressive left-wing Twitter personality Neera Tanden, the president and CEO of the Center for American Progress, who is also a former top aide to Hillary Clinton

Demos, a smaller and more left-wing think tank than CAP that is more specifically tied to the labor movement and less tied to the leadership of the Democratic Party but is still broadly in the same orbit

Joan Walsh, a former editor at large at Salon now writing for the Nation

The specific sequence of events is that Walsh published an article attacking "the presumption of moral and ideological superiority" on the part of Bernie Sanders supporters, whom she accused of "trying to overturn the will of black, brown, and female voters."

Bruenig replied:

@joanwalsh It's really about old people versus young people, but you know that. — Matt Bruenig (@MattBruenig) May 19, 2016

This parsing of the demographics of the Clinton-Sanders divide has taken on a great deal of urgency in the realm of progressive media because, presumably, casting Sanders as the candidate of white Democrats makes him look unprogressive while casting Clinton as the candidate of old Democrats makes her look uncool.

The truth is that, statistically speaking, both age and race are significant independent predictors of voting behavior in the Democratic primary.

Bruenig and Walsh had gone around on this topic before, so Walsh shot back:

Prompting a Bruenig reply:

@joanwalsh Your dishonesty on these topics is only matched by your level of animus towards young people. It's kind of disgusting. — Matt Bruenig (@MattBruenig) May 19, 2016

And an intervention from Tanden, who had also clashed with Bruenig many times over the course of the primary:

@joanwalsh Good to know this stuff isn't just for me! https://t.co/EthlLE3fdq — Neera Tanden (@neeratanden) May 19, 2016

At this point, Bruenig pivoted to an unrelated attack on the 1996 welfare reform bill:

It's fun when the geriatrics who worked to starve my mother of cash assistance get going. https://t.co/ugXi9qH7lx — Matt Bruenig (@MattBruenig) May 19, 2016

Here it should be noted that though Tanden worked for Hillary Clinton at several points in their respective careers, she was finishing up law school in 1996, not running welfare policy in the White House.

Tanden replied:

@MattBruenig @joanwalsh having been on welfare myself, don't need lectures on this topic from you. Thanks though. — Neera Tanden (@neeratanden) May 19, 2016

Then Bruenig finished off with a reference to the Scumbag Steve meme, which I will admit to never having heard of until this particular controversy.

@neeratanden @joanwalsh Scumbag Neera uses welfare when she needs it then takes away from others when they need it. Disgusting. — Matt Bruenig (@MattBruenig) May 19, 2016

@neeratanden @joanwalsh But hey I understand the hustle. You don't get to be president of CAP without starving some poor mothers. — Matt Bruenig (@MattBruenig) May 19, 2016

@AntBejarano @neeratanden @joanwalsh Neera tried to starve me and my mother because she wanted to be in Democratic politics. — Matt Bruenig (@MattBruenig) May 19, 2016

Those appear to have been the tweets that did Bruenig in.

So he got fired for calling an important person a scumbag?

Demos says it's more complicated than that.

"After multiple conversations, Matt Bruenig and Demos have agreed to disagree on the value of the attack mode on Twitter," writes Demos communications director Liz Flowers. "We part ways on the effectiveness of these kinds of personalized, online fights and so we are parting ways as colleagues today."

That makes it sound as if Bruenig left not so much for that particular series of tweets but for being unwilling to promise to act in a more restrained manner in the future. The same statement alludes to "the extent to which Matt has been at the center of controversies surrounding online harassment of people with whom he disagrees."

Describing Bruenig's fight with Tanden as "harassment" strikes me as an overstatement (more on this below), but he is certainly someone who relishes personalized Twitter combat featuring strong language and extensive impugning of motives. It's the sort of thing that most employers working in the policy advocacy space — which relies on donors for funding and coalitions for efficacy — would discourage, and it's not so surprising that a person who refuses to change it would face employment problems.

Bruenig's GoFundMe page (which has raised about $25,000), however, tells a different story: "Lost my little gig at Demos dot org for calling Neera Tanden, producer of the below policy musings, a 'scumbag.'" Sources close to Bruenig say he was told on Friday that things were too far gone and he had to leave without further discussion.

What's this welfare reform dispute about?

If you want to read a really good explainer about the 1996 welfare reform bill, the surrounding debate, and its consequences over the past 20 years, then please email Dylan Matthews, who has had such a piece on his to-do list for a while.

My bullet point version:

The US used to have a program called Aid to Families With Dependent Children (AFDC) that gave cash assistance ("welfare") to people (mostly single mothers) who didn't have a job and whose work history was too spotty to qualify for unemployment insurance. The program was poorly designed in a variety of ways and created a significant financial disincentive to work or marry, but was also a vital lifeline for millions of poor women and millions more children.

After campaigning in 1992 on a promise to "end welfare as we know it" and losing Congress to the GOP in 1994, Bill Clinton vetoed two conservative welfare reform bills in 1996 and then signed a third slightly less conservative one. This was very controversial at the time among liberals, prompting things like the angry resignation of Peter Edelman from Clinton's administration.

Given the strong economy of the late 1990s, the poverty rate fell dramatically, and welfare reformers began to declare victory. But that success has not endured into the 21st century, and many groups who were reasonably friendly to reform are now skeptical of its merits.

People involved in the Clinton administration will tell you that AFDC was politically unsustainable and that by refocusing US social assistance policy on people who were working, Democrats have been able to substantially increase assistance to low-income families over the past 20 years and greatly alleviate conditions for lower-income Americans.

Critics will tell you that welfare reform greatly increased severe poverty in the United States and we now have more than a million families getting by on less than $2 a day.

Both of these stories are essentially true. As Christopher Jencks points out in a new New York Review of Books essay, what's happened is that when properly measured we've seen a huge increase in inequality among the poor. Since 1996, most poor people have become better off, but the poorest of the poor have become worse off.

To most Democrats, this adds up to welfare reform being a mixed bag, which is more or less what Bill Clinton said when he signed a bill that he called "far from perfect" but "significantly better than the bills that I vetoed" despite his "strong objections to certain provisions."

Indeed, Tanden's stated views on welfare policy ("we have a system that decides to in some ways disadvantage kids because of the decisions their parents make, and I think that doesn’t make a lot of sense") are not that different from Bruenig's. Tanden is one of the more liberal members of Clintonland, and it's telling that you often hear her name floated for senior jobs in a Clinton administration while more conservative past advisers like Robert Rubin or Mark Penn seem to have been sidelined.

In a funny way, this angry fight between two liberals who both oppose the 1996 welfare reform law shows how much the politics of welfare — and domestic policy more generally — have shifted inside the Democratic coalition. The one thing no one has done in this whole saga is do what Clinton did in 1996 and defend welfare reform on the merits by bragging about "work requirements," touting how much smaller the welfare rolls are, or talking up the "death penalty for drug kingpins" as a key Democratic achievement.

Clinton is overwhelmingly likely to lead the Democratic Party in November just as her husband did 20 years ago. But the party she leads has evolved substantially to the left over those two decades, and that creates real tension with its younger cohort, who overwhelmingly support Sanders.

So what about the online harassment?

There is a lot of harassing behavior on the internet, and it is particularly salient on Twitter. As terrible as internet comments sections are, writers with the misfortune to express themselves on websites featuring unmoderated comments sections at least have the option of not reading them. Twitter, by contrast, is a genuinely useful tool for a working journalist, which makes it difficult to ignore even though it is a cesspool of harassment.

The force of that harassment is not felt equally. As Amanda Taub has written for Vox, "It is disproportionately women and minorities who must weigh whether covering controversial topics is worth the abuse it provokes." (Indeed, one side consequence of Bruenig's departure from Demos has been the revival of a harassment campaign against his wife, Elizabeth Stoker Bruenig, by followers of Roosh V related to a spat between the two of them a year ago.)

Bruenig's tweets at Tanden and his general approach to Twitter do not strike me as representing the kind of harassment that Taub is talking about. But part of the unpleasantness of how Twitter works is that harassment tends to operate on a continuum. Often a well-known Twitter user with a strong point of view and a decent-size following will tweet something critical of another user, and this act will unleash a torrent of critical tweets from anonymous or pseudonymous trolls, many of whom will be bona fide harassers.

I currently have 941 accounts blocked, I block more every week, and as a white man the odds are I get substantially less harassment than a comparably active woman would get.

In addition to all of this, there is the specific allegation that back in January Bruenig helped orchestrate one particular instance of harassment against Motherboard writer Sarah Jeong (some say the tweets Jeong quotes there are out of context; you can read more context here and judge for yourself) who had incurred the wrath of a circle of writers affiliated with the magazine Jacobin way back in June 2014 over something fundamentally unrelated.

The feminist writer Sady Doyle sent an email to Demos before Bruenig's firing that, while ungenerous in its accounting of Bruenig's motives and leaping to assumptions about his relationship to other tweeters, offers a window into the spillover consequences of aggressive Twitter behavior.

Demos's statement frames Bruenig's departure around these more general allegations of complicity in harassment rather than around the specific question of trolling Tanden. That has the upside of couching the move in ideologically progressive language rather than in practical institutional politics. But it has the downside of seeming, to Bruenig's supporters, like Demos is hiding the true reason for Bruenig's dismissal: that Tanden is an important person in left-of-center politics and Bruenig's core sin was calling her a scumbag.

This is about setting an example to other dissenters. Criticizing liberal elites could cost you your livelihood. Absolutely appalling. — Rania Khalek (@RaniaKhalek) May 20, 2016

The fact is that Bruenig's full-time job as a lawyer is not at stake here, at least as far as anyone knows (though there have apparently been some attempts to contact his main employer and involve them). But his part-time job writing for Demos, which he says accounted for about 30 percent of his income, involved public-facing work, and Demos, like any policy advocacy organization, is going to have a range of views and behaviors that it considers in bounds and others that it considers out of bounds.

The view that any prominent Hillary Clinton supporter is a "scumbag" who favors "starving some poor mothers" because Clinton supported her husband's signing of the 1996 welfare reform bill is probably not one that Demos's leaders would try to defend on the merits.

What does this have to do with the Democratic primary?

Everything and nothing. But it is, in important ways, a real reflection of the 2016 Democratic primary: Bruenig supports Sanders and Tanden supports Clinton, but as bitter as the fight between them has become, they're not all that far apart on the actual issues being discussed, and neither are the candidates they support.

Sanders voted against the 1996 welfare reform bill, has criticized Clinton for supporting it, and tweeted a call to reverse it without ever having released a specific plan for doing so. But following an extensive A/B testing campaign, the Sanders campaign reached the conclusion that the following website splash page is the one most likely to generate email signups and donations for the campaign.

This is exactly the political theory of the Democratic Party establishment's embrace of welfare reform — that the public will enthusiastically embrace measures to boost the living standards of low-income workers if their plight can be divorced from the problems of nonworkers.

While neither the Sanders nor Clinton campaign has directly challenged this consensus, Tanden's Center for American Progress has, with a call to make the child tax credit fully refundable — which is essentially a scaled-down version of Bruenig's signature anti-poverty initiative.

But the fight here was only partly about the issues — like the primary itself, much of the anger is driven by demographics, gender dynamics, political style, and a broader sense of procedural justice.

To pro-Clinton women, obnoxious behavior by male Sanders supporters is typical of a whole suite of social dynamics that keep women down in public life, which Clinton is struggling against. At the same time, Sanders supporters believe this focus on "Bernie Bros" and online harassment is itself a kind of cynical ploy to distract attention from the substantive issues and Bruenig losing his job is part of a larger pattern of pro-Clinton forces rigging the system against her critics.

A white man tweeting personal attacks on a woman of color and powerful members of the center-left political establishment colluding to get a vocal leftist fired both strike at the emotional cores of the respective candidates' online supporters.