Hispanics, who tend to be even "more committed to traditional marriage" than white evangelicals, are also expected to vote in record numbers this year and will likely support the proposition, according to the Rev. Samuel Rodriguez, president of the National Hispanic Christian Leadership Conference.
"Don't touch something that's part of our religious faith narrative," Rodriguez told ABCNews.com.
Still, Rodriguez said Hispanics may be the "most conservative" of all ethnic groups on the issue of same-sex marriage, but are not "homophobes," and support the "canopy" of civil rights legislation enjoyed by people of all colors and sexual orientations in California.
Now, with the fate of Proposition 8 hanging in the balance, white evangelicals have missed an opportunity to use the power of the Hispanic vote.
"There could have been a turning point if they'd engaged the Latino community," he told ABCNews.com. "Of the million of dollars invested in saying 'yes,' nothing was invested in the Hispanic community. They said, 'Any of you who are brown and speak Spanish can lead a prayer.'"
"If the proposition fails, it's a direct result of the power brokers not engaging the Hispanic community in the state of California and only in a token role, rather than sharing the leadership mantel."
But some opponents of the ban have more faith in Hispanic voters, especially the youth.
"Everyone knows it's going to be a really tight race," said David A. Lee, 52, a screenwriter who lives in Palm Springs and opposes Proposition 8. "I am really hoping it comes down to our side. The younger generation seems to be in our corner."
"Those going for Obama are not the most socially conservative," said Peter Kresel, 65, a consultant from Palm Springs who rushed to the altar before the vote on Proposition 8. "The more who get to the polls, the better, and I remain optimistic."
So, too, is Gary Goldstein, who also moved quickly to marry his partner in Los Angeles before the Proposition 8 vote. "Ultimately, I think people will make the right decision. My ads would say, 'Do not legalize discrimination for any group, especially for a group that has known discrimination.'"
Meanwhile, Stringfellow, who now works as a welcoming coordinator for San Francisco's Center for Lesbian and Gay Studies, is placing bets on the younger, black voters.
"Young people are not hung up on the same prohibitions," he said. "[Being gay] is seen as more mainstream. 'What's the big deal?' they say. I am hoping they will vote with their hearts and not what their pastors have told them."