Some passersby assume they're performing satiric street theater. Others argue with them vociferously.
"I think it's pretty shocking" for people in the Castro, Gabrielle Joyner said.
After the state Supreme Court ruled in May to allow same-sex marriage, evangelical leaders in California, working with their counterparts in the Roman Catholic Church and the Church of Jesus Christ of Latter-day Saints, began organizing to pass Proposition 8.
They launched a fundraising organization, which has raked in so many contributions that the most recent campaign finance filing crashed the secretary of state's computer.
But they also wanted a spiritual component to their campaign. Central to that is the 40-day fast, leading into what organizers hope will be a huge rally Nov. 1 at San Diego's Qualcomm Stadium. There, Engle will lead 12 hours of prayer for the passage of Proposition 8.
Though some people, including Huff, have given up solid food entirely, others are "fasting" by giving up sweets, shopping, a TV show or some other favorite indulgence. Jim Garlow, the pastor of Skyline Church -- which is hosting the fasters from San Francisco and around the country -- said almost all of his church's 2,500 members have given up something, as have members of other churches up and down the state.
Some afternoons they take a break and drive their van to Jamba Juice.
They debate which flavor is most delicious. Huff's choice is the Protein Berry Workout.
Huff said that although they are cloistered here in the rolling hills of eastern San Diego County, they feel they are doing as much or more for the cause as the political professionals who are plotting strategy, raising money and producing TV ads.
"The political cause would be a lot less effective without people praying," she said. "When they encounter the love of God, that's what changes people's hearts."