The results also shook the foundations of the Democratic Party far beyond the five boroughs. When they are certified, Mr. Mamdani, 34, and his movement will be on track to double the number of socialists in Congress from two to four. The outcome will also force a Democratic Party, already searching for its identity, to reckon with its ascendant, unapologetic left.

“It’s seismic,” said Jon Paul Lupo, a Democratic consultant who was a top adviser to the city’s last progressive mayor, Bill de Blasio.

The races do not necessarily suggest Mr. Mamdani has expanded his appeal. Each of the contests in which he endorsed took place in areas where the mayor won comfortably in last year’s election and remains deeply popular.

But Tuesday’s results showed two things about his young mayoralty. Mr. Mamdani has a high tolerance for political risk-taking, well beyond that of any of his modern predecessors. And, at least for now, he has the ability to transfer his high-wattage political brand onto other candidates in a way that only a few politicians in any office have been able to.

Brad Lander, 56, a close ally whom Mr. Mamdani urged to run for Congress, ran up a staggering 30-point margin in the affluent 10th District in Brooklyn and Lower Manhattan. He defeated Representative Daniel Goldman, a wealthy Levi Strauss heir who had opposed the mayor in last year’s elections and had close ties to the American Israel Public Affairs Committee, the pro-Israel lobby.

Claire Valdez, 36, a little-known state assemblywoman also recruited by Mr. Mamdani to run, ran up larger than expected margins for the open seat in the Seventh District in a gentrifying swath of Brooklyn and Queens so far left it has been nicknamed the “Commie Corridor.”

She defeated Antonio Reynoso, the Brooklyn borough president, who had far deeper roots in the district and the support of the popular congresswoman, Representative Nydia Velázquez, who is retiring; the left-leaning Working Families Party; and nearly every major labor union in the city.

And Mr. Mamdani’s allies even won in the predominantly Black and Dominican 13th District in Upper Manhattan and the Bronx. In perhaps the night’s most surprising victory, Darializa Avila Chevalier, 32, another democratic socialist who entered the race as a political unknown, narrowly knocked off Representative Adriano Espaillat, the influential chairman of the Congressional Hispanic Caucus.

“This is a wake-up call,” said Letitia James, the state’s progressive attorney general, who supported Mr. Mamdani’s mayoral campaign but ended up opposed to him on Tuesday.

“Obviously, there’s some hurt feelings tonight, particular in communities of color,” she said, adding, “What we have to do is sit down and work with the left-leaning part of the party and see if we can come to some sort of understanding going forward.”

Where previous mayors have taken a wide berth around intraparty primaries, Mr. Mamdani dove in. Before he even clinched his own mayoral win, he began recruiting candidates to run for seats he felt were ripe for leftist wins. He headlined fund-raisers, appeared in ads and dispatched his top political advisers to run two of the campaigns.

In the race’s final days, Mr. Mamdani exhausted himself shuttling between events with Ms. Valdez and Ms. Avila Chevalier, who were in the closest races. Wherever the mayor went, large crowds seemed to materialize.

The outcome on Tuesday could pose particular problems for Mr. Jeffries, the New Yorker in line to become speaker if Democrats reclaim control of the House this year. Ms. Valdez and Ms. Avila Chevalier have not committed to supporting Mr. Jeffries’s leadership bid and could become persistent thorns in his side.

Democrats aligned with Mr. Jeffries, who fought hard to defeat Ms. Avila Chevalier, have privately raised concerns about her victory in particular. They fear that Republicans will weaponize a trove of her inflammatory old social media posts, including her saying that “all deportations are wrong” and using crude language about Kamala Harris, against more moderate Democrats running in swing districts that will decide the fate of the House this fall.

Mr. Jeffries repeatedly sidestepped the issue during an interview on NY1 Tuesday night as the results came in. Others were less reluctant to register concerns.

“Republicans will very quickly seek to elevate, as they always do, the most radical voices in the Democratic Party,” said Howard Wolfson, a former head of the House Democrats’ campaign arm and a top adviser to Michael R. Bloomberg. “And after tonight, they will have more radical Democrats to choose from.”

Mr. Mamdani and his allies saw it very differently.

Gustavo Gordillo, a D.S.A. co-chair in New York, said that his organization was already casting its attention to next year’s budget fight in Albany and beyond.

“We’re going to start thinking about 2028 and what comes next,” he said.

>>1521255
wow corrupted terrorist mayor uses connects to help his accomplices win seats of power in a shitstain state that's literally the model for spiderman and bloody gotham city

wow, corrupted terrorist president uses connections to help his billionaire buddies that's literally the model for Kingpin and The Penguin.

>>1521255
Good. I like Mamdani. He pisses off the right people and tricks commies into supporting him.

>>1521255
Good. I like Mamdani. He pisses off the right wing and tricks them into thinking he's a commie
>[Mamdani] is a very rational man
-Donald Trump

>>1521321
>>1521333
>>1521334
Another Mamdani meltdown by /pol/, aka Russian aka epstein bots.

>>1521340
>>1521338
I like mamdani though, the only thing i hate is his association to hasan, but i'm happy if leftists suffer one way or another. Oh btw if ur white I'm happy for you I hope you meet a very friendly muslim with a ceremonial blade to show off to you

>>1521338
I said I like him. I wasn't joking. I think tRump's assessment is correct as well.
But hey, hopefully you're replying from the free bus. Oh wait, free bus rides on hold indefinitely.
I fukkin' love socialism! lol. lele even.

>>1521346
>lefitist
So a fictional boogeyman created by the fascist since liberals weren't enough?

>>1521348
i'm a liberal retard

I like Mamdani though, the only thing I like is he makes other assholes seethe, but I'm happy that rightists suffer in every way. Oh, whites are happy voting for him, just as whites are happy in making white rightards seethe by electing the white MP Andy Burnham last week. I'll be even happier when as PM he'll deny white rightards of their rights in a very friendly way.
Another rightard meltdown for /pol/tards.
It's all falling apart for the right who are eternally wrong. And seething rightards having melties should take their meds.

>>1521349
Sure you are buddy, sure you are.
That's sarcastic before you misread that.

1521347
Mamdani & Burnham will make buses free. And the latter will have subsidized train fares on a soon to be nationalized British Rail: a policy - via denying the private companies of their right to continue to own such by denying them of their right to renew their private rail company franchises - that helped Labour become the government of UK in an election two years ago.
Gotta love anything & everything that makes rightards seethe, lel

>>1521351
>>1521350
leftists should all suffer, I hope mamdami stays for a long long time, he's already given a pass to stabbings and terrorism as "racism" this is going to be a good 4 years

>>1521355
your mother just wants you to get a real job

>>1521356
ur mom never trained you so you turned out into a pissbaby, for that she deserves to be trained into a real human

>>1521355
Why do you hate Mamdami so much? Your boy Trump loves him and couldnt stop fawning over him. He even called him very handsome.

You know what really makes New Yorkers and Californians seethe? Wyoming and Alaska have as many US Senators as NY and CA. That will never not make liberal faggots seethe.

>>1521360
IDK about that anon, but personally I like him. I'm something of a socialist myself after all.
That said, I'm laughing my fucking balls off that socialists are praising this guy and he hasn't delivered on a single socialist promise. All he's done is make every other Democrat mayor look like trash by doing basic shit that should've already been done.

>esl shill doesn't understand the Connecticut Comprise

>>1521255
Chevalier is a vatnik and an actual racist.

>>1521362
>All he's done is make every other Democrat mayor look like trash by doing basic shit that should've already been done.
Yea it sucks that they cant all be perfect like Mamdami, its just that they've all been better than any republican out there. Now things are starting to change, especially with how terrible Trump has been for everybody he's more or less forced a change. The rest of the democrats can either adapt for the better, or get voted out.
Aslo.
>I'm something of a socialist myself after all.
Sure you are buddy, sure you are.

>>1521375
>Now things are starting to change
From the string of Democrat mayors?
>better than Republicans
Uh, you do know that most places run by Republicans don't have to unfuck themselves due to decades of mismanagement, fraud, waste and abuse, right?
I'm going to need some stats to backup this blue team bolstering boisterous blurb of bullshit, bitchboy.

>>1521377
>From the string of Democrat mayors?
2 Dem mayors one of which was a "former" Republican and corrupt cop literally blackmailed into working with Republicans using threat of criminal prosecution do not a string of Dem mayors make.

>>1521377
Not a self-aware bone in your body, huh?

>>1521349
Redundant.

>>1521255
That's not a dick anymore at such length.
>fucking squid

>>1521255
16 inches girth.
>practically a woman

1521362
1521355
>personally I like him. I'm something of a socialist myself
>leftists should all suffer
>I'm a socialist
>I hate socialists
The duality of the hypocrite.

>>1521389
How so?

>>1521398
The joke is all liberals are retarded. I can see how this joke went over your head.

>esl shill doesn't understand what a joke is