Standing in front of a massive “Tax Amazon” banner, Seattle City Council member Kshama Sawant declared victory in a reelection race that pitted her against Amazon CEO Jeff Bezos and the billionaire class.

“It looks like our movement has won, and defended our socialist City Council seat for working people against the richest man in the world,” Sawant said Saturday. The two-term council member, one of the most high-profile socialists and municipal leaders in the country, quoted abolitionist Frederick Douglass in front of a crowd of supporters who recognized the truth of the words, “If there is no struggle there is no progress.… Power concedes nothing without a demand. It never did and it never will.”

What happened this fall in Seattle was a great struggle—one of several in cities where proudly radical contenders confronted massive spending aimed at defeating them. Sawant won after a long count of mail-in ballots, as did San Francisco district attorney candidate Chesa Boudin, one of the boldest advocates for criminal justice reform yet to be elected in the national campaign to transform law enforcement. But it wasn’t easy.

Sawant was one of several Seattle council contenders who were demanding that Amazon and other big-tech firms headquartered in Seattle pay their fair share of taxes. Their proposals unsettled Bezos and his fellow CEOs. Amazon steered $1.5 million into races for the city’s district council seats—all seven of which were up for election this year. The money helped fund a multimillion-dollar drive by business interests to elect a corporate-friendly council that would shy away from imposing taxes on corporations, seeking to implement rent control, and otherwise tipping the balance in favor of working families that are struggling to get by in an increasingly expensive city.

A huge portion of the spending by the Seattle Metropolitan Chamber of Commerce’s “Civic Alliance for a Sound Economy” political action committee—roughly $450,000—was aimed at defeating Sawant, a member of the Socialist Alternative movement who ran a “not-for-sale” campaign that bluntly declared, “What’s at stake this year is who runs Seattle—Amazon and big business and working people.”

As The Seattle Times, which acknowledged that for many last week’s election was understood as “a referendum on the influence of companies like Amazon over the Seattle City Council,” reported four days after the election,

When the first tranche of votes was released Tuesday, Sawant trailed [Amazon-backed challenger Egan] Orion by nearly 8 percentage points. As more ballots were counted, she rapidly gained ground. More progressive candidates have tended to do better among Seattle voters who drop their ballots closer to the voting deadline. By Thursday, she was threatening Orion’s lead. On Friday, she surged past him. She currently leads Orion with 51.6% of the vote.

Sawant was not the only candidate who beat Amazon. At least five Seattle council candidates backed by the chamber’s political action committee lost. “It turns out you don’t need Amazon’s money to win an election,” announced the city’s iconoclastic weekly paper, The Stranger. “The tech company’s massive PAC spending turned out to bite them in the ass.”

This time.

Sawant’s win was a sweet victory for foes of big money in politics, especially big corporate money. But it really was a struggle. And another democratic socialist who was targeted by Amazon and its allies, Shaun Scott, was narrowly defeated.

So, while there is much for municipal activists to celebrate in the news from Seattle, the story of this year’s council competition remains a cautionary tale. “We’re talking about the richest man in the world, and the billionaire class that he’s part of, going to war against the City Council of a city,” Sawant told me in a recent conversation on the Next Left podcast. “I mean, of course, we are familiar with this kind of corporate influence on congressional races, obviously on the presidential campaign, but you can see that local elections are not immune either.”’ That’s a vital point to consider because, as Sawant says, “many grassroots movements have learned that actually it is possible to make change starting from the local level.”

While avenues for radical reform are often closed off at the national and state levels of politics, it is still possible to change things at the local level, where campaigns have historically been inexpensive. At the local level, candidates can still win district- and even citywide elections by attending forums, putting up posters, knocking on doors, and making smart proposals.

That’s been the case in Seattle, and Sawant has capitalized on the opening afforded socialists at the local level—just as Milwaukee’s “sewer socialists” did when they ran in the period between 1910 and 1960. The old lesson holds true: Bold action at the local level in one city can influence what happens in other cities and, ultimately, at the state and national levels of our politics. That scares the powerful, and the powerful have plenty of money to spend to upend progress.

“We have successfully defeated attempts at economic evictions. We are now building a powerful movement for rent control,” explained Sawant, as the election approached. “And so the billionaire class, while it initially might have arrogantly misjudged the power of local movements, is now understanding that there is a real danger that if this socialist on the Seattle City Council gets reelected once more, that will send a message of confidence. Not only throughout Seattle, but throughout the region, throughout the state, and indeed, nationwide. It is that contagion of working-class confidence that the billionaire class fears the most, and that is why they are so determined to attempt this kind of corporate takeover.”

Sawant won. And she was not the only progressive who defeated a big-money campaign. In San Francisco, Boudin was elected as district attorney, despite being targeted by roughly $650,000 smear campaign funded by the police union and its allies. “Never seen anything like it—the police union is literally trying to buy the DA’s office,” said San Francisco political consultant Jon Golinger. Boudin ultimately prevailed by around 2.500 votes.

But too many progressive candidates got beat last week, and too many more will get beat if corporate money keeps flowing into municipal elections. This is one of the reasons campaign finance reformers need to need to turn more attention to addressing excessive corporate and special-interest group spending in local races—especially when it funds what Boudin accurately describes as  “the absolute worst fear mongering, racist, hateful part of this election.” It is also why political organizers must be prepared to expose and challenge the money power at the local level—as Sawant did so aggressively in Seattle.

When Sawant says her race should serve as “a wake-up call for social movements and progressives,” she is absolutely right.