On a recent weeknight, writing instructor Ellen Tara James-Penny sits with a student in a parking lot near San José State University for more than an hour, explaining the perils of “hasty generalizations” and other pitfalls in college-level writing. Then, James-Penny and her husband get into their aging Volvo sedan and drive a few blocks to a local church, where she sleeps in their car with one dog and he sleeps in a tent a few feet away with the other.Despite the four college courses she teaches, and the master’s degree she earned a few years ago, James-Penny is homeless....