SAN FRANCISCO (CBS SF) — Salesforce CEO Marc Benioff was in Chinatown on Sunday campaigning for Proposition C, the controversial plan to curb the city’s homeless crisis with tech money.

Prop C would be the largest tax increase in San Francisco history. It would tax corporations 0.5% in gross receipts if they make more than $50 million.

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Prop C would raise roughly $300 million annually. The money would go to creating housing for around 5,000 people, providing 1,000 new emergency shelter beds and funding mental health programs.

“We know that we have to get people off the streets. We need more funding. We can do more,” said Benioff.

A crowd of roughly a couple hundred people gathered for the “Yes on C” rally of which Marc Benioff was the guest of honor. Benioff gave $2 million to support the measure.

Opponents of Prop C argue that though San Francisco has tripled its spending on homelessness in the last decade, the problem has gotten worse.

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“Without additional accountability, we might be throwing good money out with the bad,” said Jesse Montejano of No on Prop C.

Opponents also warn that Prop C may have a negative impact on jobs, housing and transportation costs.

Prominent politicians such Mayor London Breed and state senator Scott Weiner oppose Prop C, but tech executives have taken center stage on the issue.

Benioff and Twitter co-founder Jack Dorsey have exchanged lively tweets on what would be the best solution.

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“I really have to thank Jack Dorsey because he gave us a national conversation on Prop C,” said Benioff.