The Illinois senator’s fourth California office opened Thursday night on Q Street between 20th and 21st.

Obama’s California state director, Mitchell Schwartz, says the campaign originally didn’t plan on opening a Sacramento office at all. But that changed, thanks to demand from local volunteers.

Schwartz: “The resources that it takes to open an office is not that much. It’s rent for a month and a half, it’s computers, phone lines, and you know, these things aren’t cheap, but the big expense of a campaign would be paid staff or paid television or paid advertising and we’re not doing it.”

Schwartz says the office will become a home base for training, phone bank and canvassing operations.