California’s Proposition 8, which would ban same-sex marriage, has taken in about $20 million from the Mormon Church and its members, including a recent $1 million contribution from the grandson of a president of the church, according to the No on 8 campaign.

Those staggering sums, coupled with plans for a giant Yes on 8 rally in San Diego on Sunday, in which James Dobson is expected to attend, have supporters of same-sex marriage fearful of their prospects come Tuesday.

The No on 8 campaign plans a bus trip through the state, starting at Santa Monica Pier on Saturday morning, with Mark Ruffalo among those on hand to speak against the constitutional amendment. And on Friday, Republicans Against 8 plan to release a Web video featuring highlighting Ronald Reagan’s opposition to an anti-gay initiative 30 years ago as well as Gov. Arnold Schwarzenegger’s stance against 8 this year.

In the meantime, there’s still plenty of buzz among bloggers and fund-raisers on who has not contributed to the No on 8 campaign. Fund-raisers who raised $4 million at a Beverly Hills event last week say that no studio heads or studios have contributed, even as companies like Apple and Google have chipped in to defeat the ballot measure. Their argument has been that it is not taking a stance on a political issue but a civil rights issue.

Out in Hollywood’s Greg Hernandez singles out Rosie O’Donnell and cites the lack of mention on her blog. He writes that he finds “it kind of mind-boggling that she is writing about “Real Housewives of Atlanta” and old Reese Witherspoon” movies and not a word about Proposition 8. I am curious about why Rosie, always so outspoken, has been so out of the picture.”

Other personalities like Ellen DeGeneres have written on their blogs and contributed sums to the effort. DeGeneres bought $100,000 worth of ad time to run a spot in which she speaks out against the proposition.

Hernandez also speaks to Bill Maher about same-sex marriage.

“It is ugly because it’s prejudice,” Maher says. “It’s denying people their civil rights. And it all comes from religion. If there wasn’t a Bible, no one would ever think twice about homosexuality. It’s obviously something that occurs in nature. It’s just that it says in the old book of Jewish fairytales that you’re not supposed to do it with people of your own sex.”

As for the influx of money from religious groups, Maher says, “I think it’s amazing in this tough economic climate that people are digging into their wallets and purses to give money to this issue which affects their life not at all. What do they care if gay people get married? It’s astounding to me how unimportant this issue is and it still drew something like $25 million (in donations).”

A note: I married my same-sex partner last week, it’d be a leap to say that I am neutral on this proposition, although I have tried my best to be fair to both sides in covering this story from the industry angle.

Update: The latest polling shows the race in a dead heat, and there’s expectation of new Field Poll numbers tomorrow showing the No side up.