When Umbelina Martinez’s family first came to the United States decades ago, from ­Michoacan, Mexico, they settled in a three-bedroom house in Redwood City, Calif. It wasn’t all theirs; 25 people lived on the property, sharing a single bathroom. Martinez’s family of eight squeezed into one bedroom. “My mom and dad had to step over us kids to get to the door,” she recalls.

Today, the 46-year-old single mother of three has much more spacious accommodations: a 200-square-foot mobile home in a trailer park in Palo Alto, the heart of the technology industry and one of the most expensive cities in the country. She has lived there 13 years.

“Who wouldn’t wish to live in Palo Alto?” she asks, seated in her kitchen, which doubles as a living room, dining room, and storage space. Its thin walls ar

See Full Page