After years of secretly snapping up property for plans to build a new California city, a company backed by Silicon Valley billionaires is taking the pitch to voters. The California Forever company submitted paperwork Wednesday to ask voters on the November ballot to allow them to build the city on now protected agricultural land. The company has ducked scrutiny while snapping up more than $800 million of Solano County farmland in recent years. The plans would include nearly 20,000 homes initially for 50,000 residents and could grow to 400,000 people.