Longtime incumbent Democratic Rep. Michael Capuano (D-MA) lost his primary on Tuesday to anti-establishment insurgent Ayanna Pressley in the latest of a series of powerful incumbents to lose to grassroots-fueled outsiders.

Holy cow! Per @kelleratlarge, Ayanna Pressley has beat Mike Capuano! https://t.co/8wY7amBMKK — Matt McDermott (@mattmfm) September 5, 2018

Capuano conceded the election early after returns started flowing in, a sign of how badly Pressley defeated him.

It appears the hard left Democrat Capuano was not leftist enough for even leftist Massachusetts:

This win for the hard-left of the Democratic Party against its own establishment comes in the wake of devout socialist Alexandria Ocasio-Cortez’s stunning upset win over Rep. Joseph Crowley (D-NY) in New York earlier this summer, a shocker that rocket-fueled the leftist wing of the Democratic Party in a year where establishment incumbents are having a hard time winning re-election.

A glowing profile of Pressley in the New York Times published with a Cambridge dateline just a few days before the primary on Tuesday reveals just how unusual she is:

It’s not a sight you see every day, certainly not around Boston — a black woman mounting a plausible challenge to a 10-term white congressman from her own party, a politician with vast connections who votes the progressive line and opposes everything Trump. But here was Ayanna Pressley, a Boston City Council member and rising Democratic star, exhorting volunteers in a Cambridge restaurant with an impassioned performance style she learned as a child at her grandfather’s storefront Baptist church in Chicago.

The piece goes on to quote her about how she plans to lay out a leftist agenda, and not just provide “resisting and affronting” to President Donald Trump.

“This is not just about resisting and affronting Trump,” Pressley said, per the Times. “Because the systemic inequalities and disparities that I’m talking about existed long before that man occupied the White House!”

Pressley is backed by Alexandria Ocasio-Cortez, the leftist socialist who defeated Crowley in New York on a message of pushing to “Abolish ICE.” Pressley herself also backs abolishing the federal agency that handles immigration enforcement, Immigration and Customs Enforcement (ICE)–and other pillars of a socialist agenda like “Medicare for all” and widespread gun control:

The times require and our district deserves bold activist leadership. A champion who will fight for: ✅Medicare for all

✅Abolishing ICE

✅Ending the gun violence epidemic

✅Eliminating the cash bail system

✅Women’s bodily autonomy

✅Justice#changecantwait — Ayanna Pressley (@AyannaPressley) September 3, 2018

And on social justice issues:

Also, @AyannaPressley opposed a bill to protect police officers from assault, which @mikecapuano voted for: https://t.co/DSBeXAvBGc — Joel B. Pollak (@joelpollak) September 5, 2018

Ocasio-Cortez backed Pressley in her race in interviews and tweets:

“The people closest to the pain should be closest to the power.”

– @AyannaPressley. Vote her in next, Massachusetts. There are more of us, too: @CoriBush, @Chardo2018, @AyannaPressley & more. We need to elect a corporate PAC-free caucus if we’re going to get things done. https://t.co/M2tF5cedTs — Alexandria Ocasio-Cortez (@Ocasio2018) June 27, 2018

And in a CNN interview, Ocasio-Cortez pushed Pressley’s campaign:

"We won because I think we had a very clear winning message and we took that message to doors that had never been knocked on before," says 28-year-old political newcomer Ocasio-Cortez on her win in NY's 14th District Democratic primary https://t.co/QPoCbqeFNr pic.twitter.com/CiEnZD3Ry0 — CNN Newsroom (@CNNnewsroom) June 27, 2018

Pressley, for her part, returned the favor, tweeting congratulations Ocasio-Cortez’s way:

A huge congrats to @Ocasio2018 for your victory tonight! You proved that when we stand up for what we believe in, we win. This is about more than one campaign or election. This is a movement. Together, we will change the world. Congratulations! #ChangeCantWait #Ocasio2018 pic.twitter.com/imORpc1jST — Ayanna Pressley (@AyannaPressley) June 27, 2018

A piece in Boston.com profiling Pressley’s race after Ocasio-Cortez’s victory this summer noted the similarities between their two campaigns.

“Pressley, who became the first woman of color ever elected to the Boston City Council in 2009, has launched her own insurgent primary challenge in Massachusetts, taking on longtime Rep. Michael Capuano in the state’s 7th Congressional District,” Nik DeCosta-Klipa wrote.

“The nature of the 44-year-old city councilor’s [Pressley’s] campaign — a woman of color taking on a white, male longtime congressman in a Democratic primary — drew immediate comparisons [to Ocasio-Cortez’s campaign] Wednesday,” he added. “The similarities and ties don’t end there, though there are some key differences.”