Jan Sramek has spent the last few months in restaurants and conference rooms presenting to politicians, environmentalists and unions a plan to erect a new California city on open farmland in an eastern corner of the San Francisco Bay area. The project is backed by a number of big names in Silicon Valley, including venture capitalists Michael Moritz and Marc Andreessen, LinkedIn co-founder Reid Hoffman, and Emerson Collective founder Laurene Powell Jobs.

a tan event On Wednesday night, Sramek, CEO of a company called California Forever, took his case to Solano County voters.

The crowd was not convinced.

Before the event began, protesters had gathered on the steps of the meeting venue, the Vallejo Historical and Naval Museum, with signs reading: “Transparency, not deception” and “Flannery will ruin California FOREVER.” During the event, attendees complained about billionaire Sramek supporters, said they worried a new city would displace current residents, and confronted jobs conversations with questions about data.

Mr. Sramek took it in stride, answering questions patiently and appearing mostly unfazed. He promised improvements in infrastructure, jobs and middle-class housing for the county’s 450,000 residents.

“If not here, where?” he asked the crowd of about 100 people.

“Not here!” shouted one audience member.

Many of the protest signs referenced Flannery Associates, a subsidiary of California Forever, which in the last five years has spent $900 million to buy more than 50,000 acres of farmland. The company said little about its backers or their intentions, leading to wild speculation about what the company’s plans were until August, when The New York Times reported the identities of the backers and their hopes for a new city. Some thought it could be the site of a new Disneyland; others, including members of congress, he was worried that a foreign government was behind this. (Flannery’s land now surrounds Travis Air Force Base.)

The revelation that Flannery is actually not a spy operation but a developer looking to develop has done little to quell anxiety, but instead turned one kind of fear into another. On Wednesday, the skeptical crowd threw Mr. Sramek questions on a variety of topics: the potential for traffic, whether the development would interfere with the base where many Solano County residents work and, by the way, where would they get their water? for a new city?

Over the coming months and years, California Forever will likely focus on one overarching problem: Most of what it wants to build is currently not permitted. To change that, the company would need to overcome a number of hurdles that require blessings from local, state and (potentially) federal governments.

The first of those obstacles is Solano County’s long-standing policy slow growth ordinance, whose goal is to direct development to existing cities. California Forever has said it would hold a ballot initiative next year to amend the ordinance, appealing directly to voters.

Another question that continues to haunt the project is why California Forever wants to build in a rural area far from the urban core of the Bay Area; in other words, why you want disorderly expansion. Although the event took place in Vallejo, a coastal city of 120,000 inhabitants that is The largest in Solano County., the land in question is an hour’s drive away and consists mainly of hills covered with sheep and wind turbines. Sramek has repeatedly responded to the accusation that he is promoting urban sprawl by saying that, while he favors “infill” development in existing cities, he has not produced enough housing to meet the region’s needs.

“The definition of insanity is to keep doing the same thing over and over again and expecting it to change,” he said Wednesday.

During a slide presentation, Sramek attempted to reassure attendees with vignettes about the project, its sponsors and his own background (Goldman Sachs, “but left to found an education company that helped workers learn new skills”). He said plans for the precise location of the project would be revealed next year. Meanwhile, California Forever has created a more impressionistic image with computer generated images like a tree-lined street of terraced houses with cartoon children riding bikes in front.

Many of Mr. Sramek’s assurances came in the form of promises about what the project would not be. A slide that said, “What we’re not doing,” listed the swamp the company doesn’t plan to build on and the prairie it would avoid. California Forever will not build “a gated community for the rich” and will not “tell Solano County what to do.”

If the company was granted permission to build, many construction jobs would be created. During the meeting, Mr. Sramek raised the possibility of other benefits, but stopped short of committing. One slide said “ideas being discussed” included down payment assistance for homeowners, money to rebuild Solano County town centers and funding for local nonprofits.

“There is nothing more democratic than saying ‘We have an idea to improve Solano County; We believe in that idea so much that we are going to invest $900 million,’” Mr. Sramek began in an exchange.

“In secret!” someone shouted.

After the meeting, one attendee, Phillip Balbuena, a 43-year-old facilities manager, said he had moved to Solano County after the price drove him out of the city of Fremont, which is a bridge from the heart of Silicon. Valley. His fear was that the project would pressure prices and force him and others to move again.

“We are already overloaded,” he said.

Criticisms like this get to the heart of the Bay Area’s and the nation’s housing problems. The root of rising rents and home prices in California is a long-term shortage in the number of units. But residents remain wary of development to alleviate it and are resentful that most of the new housing is intended for higher-income families.

“It’s really simple: We’re just not building enough houses,” Sramek said Wednesday.

Sramek’s argument about the housing shortage was in line with arguments that California lawmakers, a large majority of them Democrats, have been making for the past decade. But the size of his proposal, the backing of some of the richest people in the world and the fact that his company spent five years hiding his intentionsIt overshadowed the political debate that it seemed to want to have.