For better or worse, current U.S. law and jurisprudence gives religious organizations wide latitude to engage in (ostensibly non-partisan) political activism and lobbying.
For instance, my denomination, the Presbyterian Church in the United States of America (catch it while you can), recently spent its tax-exempt dollars to compose a report calling on the U.S. government to stop sending aid to Israel until Israel stops building settlements in the occupied territories. As if the U.S. government (or even your average Presbyterian) cares what the PCUSA General Assembly thinks on matters of foreign policy. I was amazed when I attended the 2002 General Assembly that the delegates felt it was a good use of time and money for the church to pass judgment on U.S. policy toward Columbia and drilling in ANWAR. One has to admire, however, the stubborn hubris and custodial impulse of mainline Protestantism.
The Presbyterians catch little flak for their politicking because it's not especially extensive, because non-Presbyterians can't spell or pronounce the denomination's name, and because no one imagines the church might have any actual political impact.
The Mormons are not so lucky (or unlucky, if you want your efforts to be noticed). Their political activism has made a tangible difference in recent years, and everyone pays attention. The evangelical Right and the secular Left both find the church problematic, evangelicals for theological reasons and secular liberals for both theological and political reasons.
I was struck by the reaction to the Latter-day Saint effort to pass Proposition 8 in California in 2008. I consider it quite normal, though not always wise or beneficial, for churches to involve themselves in political matters. The Catholic Church does so, liberal mainline denominations do so, and evangelicals do so. Lots of non-religious tax-exempt organizations also devote themselves to political, even quasi-partisan causes. In general, I think this is good for American democracy. It introduces a broader range of opinions and ideas into our political discourse, especially if religious organizations frame their arguments in ways that appeal across religious lines. Also, as Jon Shields has argued, religious activism over "social issues" like abortion has encouraged new segments of the American population to become politically involved.
A recent documentary, 8: The Mormon Proposition, examines the church's involvement in the campaign. Religion Dispatches posted a favorable review two weeks ago. Here's a snippet of my contrary review:
Mormons do place an extraordinary emphasis on obedience to their leaders, including viewing their president as God's ordained prophet on earth. That ethic of obedience does not, however, make Mormon leaders cruel dictators or ordinary members blind automatons. While Mormons in California and elsewhere heeded their leaders' call, most probably did so not out of fear or blind obedience but because they also believed in the cause.
... Ultimately, where the film really misses the mark is in its portrayal of Mormons—less than 2% of Americans belong to the church—as a threat to fundamental American political values. At various points in U.S. history, Protestant Christian majorities persecuted Quakers, Mormons, Catholics and Jews. Until recent decades, racial majorities deprived African Americans, Chinese Americans and other groups of basic citizenship rights.
As a small, non-violent minority, the Mormons pose no such threat. The specter of Mormon money raised in the film seems like a latter-day version of older fears about Jewish financiers controlling the American economy and government. The Mormon effort made a difference only because Californians are roughly evenly divided on the issue of same-sex marriage.
I have no problem with polemics, but they need to be convincing. I found myself very suspicious watching an ex-Mormon describe Mormon theology. Couldn't the filmmakers have at least found a more neutral never-been-Mormon to discuss such matters? And I wanted to hear some articulate, kind church members discuss their decision to support the campaign. Most of the Mormons I have met are far more intelligent, reasonable, and humble than the Proposition 8 supporters showcased in the film.
A few other thoughts on the film. Reed Cowan, the director, initially intended to make a film on the pain and suffering LGBT youth in Utah encounter from family members and church leaders who reject them. That section of the documentary is very powerful, and its message certainly transcends Mormonism. Most Christian churches need to repent for their past treatment of gay and lesbian members / parishioners.
I do think the film's basic narrative is correct -- Mormon money and elbow-grease did make a difference and probably got Proposition 8 over the finish line. [I just don't think that Mormons deserve to be vilified for having done so]. The supporters of Proposition 8 -- Mormon and otherwise -- out-politicked the opponents by shifting the focus from marriage per se to the broader ramifications of gay marriage on educational policy, adoption agencies, and religious freedom. Instead of dismissing such issues as wild distortions, supporters of gay marriage might more successfully appeal to wavering voters by finding a way to straightforwardly assuage such concerns.
Coincidentally, the Presbyterians also voted to ordain gays and lesbians as pastors. That decision now heads to the church's presbyteries for ratification, which a similar measure failed to obtain a few years ago. At the same time, the PCUSA decided not to amend its own language on marriage, keeping its definition of marriage as between "a man and a woman" rather than changing it to between "two people." I think debates over issues like abortion and gay marriage are healthy for American democracy, but there won't be any more PCUSA Presbyterians left by the time we've made up our minds on questions involving homosexuality.