Several clarifications on this church and 501(c)3 stuff and what I think about it, sorry this has been too long in coming, I'm just swamped with work and school.
Suffice to say:
1. I probably spoke too soon about the Mormons. As much as I hate the idea of spending church money on those ads, it was legal for them to do so. Probably it should remain so. I have a basic mistrust of the idea of 501(c)3s using their money to lobby for things and tend to think lobbying groups should be separate from religious and charitable organizations so that you can give to the second without giving to the first. But that's not the way the law is written and I think most people would probably disagree with me.
I know a little bit about lobbying, what works and what doesn't, and I think a vast majority of lobbying money and efforts are for all practical purposes wasted. I think the UUA and the UU organizations that do it could be actually helping people with the money and time they spend on it. If nothing else, it doesn't encourage me to give them any money.
The Mormons spent a lot of money that could have done a lot of good, but their ads were effective in getting the legislation they wanted. Yet at the same time, I wonder if ten years from now even they will consider it a good investment.
2. As much as I hate it when UUs say "People are suffering, clearly we should lobby the government to do something about that" rather than trying to solve the problem themselves, that also is legal. Things do happen in UU churches sometimes that run afoul of the law as written, but we don't make a habit of it. Yes, most of us could string together a few anecdotes and make it SOUND like a habit, but a few anecdotes in a lifetime of churchgoing does not a habit make.
3. The stories written by life-long Mormons who are leaving the church over the proposition 8 issue break my heart and I hate to think we do that to people on the other side politically, though I know we do.
4. I agree with Joel that UUs, particularly President Sinkford, have gone over the line in the past in delineating "good people who agree with me vs. everybody else who is racist/classist/all around stupid/evil." Joel's example of Sinkford writing that those who agree with him on illegal immigration are "people of conscience", and are "called to acknowledge that racism has blinded most Americans" seems a good example to me.
I would never want such statements to be in themselves a violation of our tax status, but I really think they suck and do more damage to the church than most people who agree with them realize.
5. I think lobbying gives us something to point to that "We" are doing to help those in need without actually doing any work.
So I hope that helps. I should have been clearer on some of that stuff from the beginning.