Sue’s thoughts: sue the IRS to compel stripping the Mormon Church of their tax-exempt status. It might work, because their Yes on Prop 8 activities appear to violate laws forbidding non-profits to engage in political activity. She specifically focuses on who might have the right to sue:
In the 1980’s, Abortion Rights Mobilization and other plaintiffs sued the IRS in an attempt to compel the revocation of the Catholic Church’s tax exempt status under 501(c)(3).
The Catholic Church had been campaigning vigorously against abortion rights, and pouring a lot of money into their cause.
The case went all the way to the Supreme Court, which held that the plaintiffs had no legal standing to bring the suit.
As I understand it, “standing” is the right to initiate or participate in a legal action.
Under Supreme Court doctrine, those bringing lawsuits in Federal court must first demonstrate that they have standing to sue, usually by showing that they have suffered in some concrete way.
In the earlier Appeals Court decision, the judges determined that some of the plaintiffs had no injury beyond their “discomfiture at watching the Government allegedly fail to enforce the law with respect to a third party,” and that the abortion rights organizations did not have standing as competitors because by refraining from political activity, “they choose not to compete” with the church.
In the current matter, churches (LDS most prominently) seek to curtail the ability of the state to govern civil unions, and the ability of same-sex couples to marry. They wish to deny a plethora of legal benefits that go hand-in-hand with being married under the law.
Hence, you have injured parties, not hypotheticals.
I am not an attorney, I am a forensic accountant. Therefore I cannot argue the issue of legal standing vis-a-vis same-sex marriage. But it seems worth asking a civil rights attorney about.