Pundits close to the Democratic establishment have a new term to fling at the left-wing insurgents they want to disappear: “factionalism.”

Matthew Yglesias now constantly attacks socialists and their leading figures on the basis that they believe in “factionalism and anty-partyism,” or have “a whole factional project,” “factional talking point[s],” a “passion for factionalism.” At first, he took up this line over the Graham Platner candidacy, but now Yglesias uses it to refer to any attempt by the Left to replace establishment-friendly incumbents by beating them in primary races.

Center for American Progress President and CEO Neera Tanden agreed. Platner should have been solely attacking his Republican opponent, “not attacking Dems in factional fights,” she tweeted. Socialists had to be stopped from “giving away the Michigan Senate seat for factional reasons the way they tried (and likely succeeded in) giving away the Maine seat,” warned former George W. Bush speechwriter David Frum.

Even the cryptocurrency industry has gotten in on the act, with crypto investment firm executive and former Securities and Exchange Commission official Justin Slaughter adding his voice to the chorus warning that the Platner scandal was the doing of “a coherent and focused faction” more interested in remaking the Democratic Party than beating Donald Trump.

This line is a bit rich. In a phenomenon known as “mirror politics” or “accusation in a mirror,” the centrist figures pushing this talking point are accusing their leftist political opponents of the very thing they want to do — the very thing their side has already repeatedly done, in fact.

As one example, recall that to stop Bernie Sanders from winning the nomination in 2020, they coalesced around a candidate, Joe Biden, who they had openly acknowledged was cognitively unfit and whom they had little faith in. As we found out last year, Biden was so out of it, when they filmed him interacting with ordinary voters for that year’s Democratic convention, those who saw the footage were alarmed and convinced he couldn’t serve, and it required “creative” editing to salvage.

In other words, the factionalism-driven election disaster that party centrists are now accusing the Left of trying to engineer is exactly what they already did, handing the White House to Trump a second time because they were so desperate to stop Sanders. As Biden’s own adviser acknowledged, that this didn’t happen was only thanks to pure dumb luck, after a global pandemic meant Biden didn’t have to campaign or be regularly seen in public. Self-defeating “factionalism” is alive and well in the Democratic Party — but it’s coming from the establishment side.

But there’s a more important point to be made here, as well as a cautionary tale for those willing to learn from it. It happens to be related to the likely place that gave Yglesias, Tanden, and the like the idea to start spamming this word, “factionalism”: the United Kingdom.

Five years ago, the UK’s Labour Party got exactly the party leader that establishment centrists dream of getting here: a dull centrist lawyer who more or less looked like what AI would spit out if you asked it to show you a British prime minister. Keir Starmer complained endlessly about “factionalism.” And just like Tanden and Yglesias, Starmer used this gripe against “factionalism” — by which he meant the party’s swing to the left occasioned by a democratic process won by a flood of energized, young members into the party — to launch an actual factional war against his party’s left.

Once leader, Starmer spent years systematically purging that left from the Labour Party, a campaign that often involved heroic levels of shameless hypocrisy. He suspended then booted his socialist predecessor, Jeremy Corbyn, from the party, a man he had once pretended to be an ally to and called a “friend.” He demoted several socialist MPs and continued suspending left-wing members any time they dissented. He banned left-wing intraparty groups and expelled their members, disproportionately targeting those of Jewish descent (while saying he was focused on “tackling antisemitism”). He made a series of arcane procedural tweaks to weaken the party’s left wing, cracked down on local branches controlled by the Left, and tried to get rid of the democratic process that let grassroots party members elect the leader (which is how the Left had taken power in the party in the first place).

The idea was that Labour had to reject its left wing to look more serious and electable, and that, once it won, with its radicals and lefty firebrands out of the picture, it could govern from the “sensible center,” ushering in a new golden age of liberal governance.

Five years on, how did this idea work out? Well, Starmer and Labour did win the election in 2024 — although polling showed voters were largely driven by hatred of the disastrous Conservative government, and Labour had won one of the more unusual landslides in politics, where its actual vote share had only gone up 1.6 points from its defeat under Corbyn to win barely more than a third of the vote.

That would turn out to be the high point of the Starmer experiment. Having muzzled any internal dissent from his left flank, Starmer embarked on a series of lethally unpopular neoliberal governing choices that would send his and his government’s approval ratings into free fall.

His decision, for instance, to make cuts to winter heating subsidies for pensioners, while simultaneously having taken a record amount of lavish gifts from a superrich donor, saw his personal popularity plummet to its lowest ever level after only two months (though he no doubt would’ve been pleased that he had become more popular among Conservative voters in that time).

The hits kept coming. Labour was decimated in the following year’s local elections in a major victory for the hard-right Reform Party. Starmer then lurched even further right in response, disgusting even more Labour voters and sending his favorability rating to a new nadir of -46 percent. Satisfaction ratings hit the lowest point for any prime minister in nearly fifty years, and Labour achieved the worst first-year polling drop of any governing party ever. Then Labour got another drubbing in this past May’s local and regional elections, which were viewed as a referendum on his leadership.

By the time Starmer resigned last month, he was widely considered a failure, the most unpopular British prime minister in polling history and a deeply hated one, who not only left his once-dominant party in a state of collapse and vulnerable to its first serious left-wing challenger in forty years, but may well end up having paved the way for the country’s takeover by the far right.

Starmer achieved this parade of humiliations by doing exactly what the likes of Yglesias and Tanden dream a future Democratic candidate will do: he governed with no real convictions; stuck close to big donors and neoliberal operatives who ended up creating scandals for him; was pro-business and sharply anti-immigration; went above and beyond to defend Israel’s genocide in Gaza; and, of course, he went to war with his party’s left. And as a result, he may have destroyed his party and certainly turned himself into one of history’s embarrassments.

There’s no reason to think this would go any different here. In fact, we’ve already gotten a taste of it. Two of the loudest figures attacking progressive “factionalism” right now both had a direct hand in the political conditions that brought Trump to power a second time: Tanden, who served as Biden’s adviser during his rightward pivot; and Yglesias, by being one of the most-read pundits in his administration, during which time he was serving Biden advice that people were wrong about their affordability struggles and the president should keep ignoring them.

Meanwhile, to deliver the White House to Trump a second time with her uninspiring centrist campaign, Kamala Harris actively sought out the expertise of Starmer’s inept advisers, who told her to focus on winning back voters drifting right, partly by presenting as an immigration hawk. Even though Starmer and his party’s approval was at that very point collapsing, she listened to them.

It doesn’t have to be this way. Just look at — and I can’t believe I’m writing this — New York governor Kathy Hochul, a conservative Democrat who, rather than going to war with the socialist mayor of her state’s biggest city, has governed in a loose coalition with him, even adopting some watered-down versions of his flagship policies as her own. That’s been a mutually beneficial arrangement for both of them, as Hochul moves to address New Yorkers’ affordability concerns in advance of her reelection.

As socialists continue to win elections around the country, you will hear more and more from the panicked voices who claim that democracy is some kind of nefarious plot against them. Driven by petty grudges and ideological resentment, those voices will only get more frenzied the more these wins stack up. Don’t take them seriously.