A measure to tax wealthy companies and fund homelessness services that saw tech titans trade insults passed with overwhelming support on Tuesday

Proposition C is expected to raise an estimated $250m-$300m in additional revenue for services for the estimated 7,500 people who sleep on the sidewalks each night.

As of Wednesday, with 100% of ballots tallied, the tax passed with 60% of the vote.

“I feel like this is really built on decades of organizing and really creating the conditions that made last night’s victory possible,” said Jennifer Friedenbach, the executive director of the Coalition on Homelessness, one of the architects of Prop C. “It’s been a battle just to hold our basic humanity in San Francisco. It’s been a real battle, but we’ve been able to do that, and that’s why we were successful.”

The tax became the hot-button issue within the tech industry this election cycle, with billionaires keeping the measure in the headlines with very public fights and donations for or against it. Opponents of the measure say the tax will drive business from the city, while proponents point out that homelessness in San Francisco has become a humanitarian crisis in part because of the tech boom contributing to rising housing costs.

Salesforce’s CEO, Marc Benioff, led the charge for the measure, funneling millions of his own money to the “Yes on C” campaign and calling out the tech giants who opposed it.

He tweeted on Wednesday: “Prop C’s victory means the homeless will have a home & the help they truly need! Let the city come together in Love for those who need it most! There is no finish line when it comes to helping the homeless.”

Jack Dorsey, CEO of Twitter and Square, was one of the most outspoken critics of the measure, saying he did not believe it was “the best way” to “fix the homeless problem”. Many criticized his stance, pointing out that Twitter has long benefited from a massive tax break to operate in San Francisco. The Zynga co-founder Mark Pincus drew similar ire when he tweeted that “Prop c is the dumbest, least thought out prop ever” (sic) – Zynga received a tax break similar to the one Twitter received after it copied Twitter and threatened to move out of San Francisco.

Dorsey did not tweet again about Prop C on Wednesday, nor did he respond to requests for comment. Pincus tweeted, “Some good election results. 100 women elected to congress, gavin as gov, and even prop c, which we will all work to make a success for sf homeless.”

The influx of wealth that accompanied San Francisco’s second dotcom boom created massive economic disparities and drove up the housing market, fueling frosty relations between the locals and the new tech transplants. The “move fast and break things” mentality of the industry pushed forth the stereotype of the entitled yet unengaged techie, as did the various diatribes and open letters penned by startup founders and entrepreneurs complaining about the homeless “riff-raff” and “degenerates” they were forced to encounter on the streets on their way to work.

But in the years since the boom first began, the tech workers have had time to live and grow in this city, and come to think of it as their home. Many of the volunteers for the Yes on C campaign were tech workers, said Friedenbach.

Inequality and surging homelessness have come to define San Francisco. Photograph: David Levene/The Guardian

“We needed 9,000 signatures to get on the ballot, and we ended up getting 28,000 signatures, and a big reason for that was that a lot of the people out there getting signatures were tech workers,” she said. “And every time a company came out against Prop C, their workers revolted on some level.”

And because of the campaign donations from Salesforce and Benioff, Friedenbach said the campaign was able to immediately help some of the homeless in providing jobs.

“We had already planned on hiring homeless people,” she said. “We had a budget for hiring 40 but we were able to increase the wages and hire about 200 homeless people to make phone calls, knock on doors, and do the work. And we wouldn’t have been able to do that without the Salesforce funding. For folks that are out there, homeless people languishing on those waitlists, just being able to value them as human beings and to fight side by side with them has just been a really transformative experience.”

The Yes on C campaign had hoped for a two-thirds majority vote to bypass any legal challenges. In 1996, California voters passed Proposition 216, thereby requiring a two-thirds majority for any new tax measure where the proceeds are used for specific purposes. But the city attorney’s office has interpreted a 2017 state supreme court ruling that a tax measure put on the ballot by citizens, not government officials, required only a simple majority to pass.

The city has already prepared for the legal battle, with the controller, Ben Rosenfield, asking the mayor and the board of supervisors to put the tax funds raised by Prop C into a reserve until any legal dispute is resolved.

Friedenbach said she is not too concerned about any legal challenges. “We have a strong city attorney’s office,” she said.

Instead, she is focusing on the work ahead. In the 23 years she’s worked with the coalition, she has not had the opportunity to enjoy a lot of victories. But on Tuesday night, she got to look out into a crowd of people, many of whom were homeless or formerly homeless, and celebrate.

“They were really feeling hope for the first time,” she said. “They had been languishing on these waitlists for housing for years and years on end, and now a pathway off the streets is something they can visualize.”