Undeterred, supporters took their case to the state Supreme Court in California, who overturned the state’s same-sex marriage ban last May. By June, couples were marrying, but in November voters passed Proposition 8 to again ban same-sex marriage. About the same time, however, the state Supreme Court in Vermont ordered same-sex marriage legalized, bringing the states with such laws to two by the end of last year.

Thus far, 2009 has been a busy year for people on both sides of the debate, with more victories going to supporters of same-sex marriage. The Iowa Supreme Court ruled that same-sex marriage is legal and couples started wedding April 27. In spring, New Hampshire signed into law a bill to legalize same-sex marriage beginning on New Year’s Day, and Vermont’s state Legislature overturned their governor’s veto of a bill to allow same-sex marriage beginning Sept. 1. Two weeks after that date, same-sex couples in Maine will be allowed to wed, as well.

The American people are supporting same-sex marriage more than ever before. A Washington Post/ABC News poll last month showed 49 percent of people believing it should be legal versus 46 percent who said the opposite. This marked a sharp and significant shift in opinion from when the same poll was conducted three years prior when 58 percent said same-sex marriage should be illegal versus 36 percent said it should be legal. Interestingly, two groups that showed especially large swings in opinion in favor of same-sex marriage were younger voters and Catholics.

Byrnes and her supporters would be well-advised to take a long and deep look at the 2004 battle over same-sex marriage in Michigan as well as these more recent developments as they plan their course of action. In May, the Center for American Progress, a liberal think tank with significant influence in the Obama administration, issued a report called “The Faithful Divide Over Wedding Vows: A Profile of Michigan’s 2004 Battle Over Marriage Equality” that took such a look and made recommendations for future efforts. Among the authors’ findings was that the use of religion by supporters of Proposal 2 (those who opposed same-sex marriage) played a significant role in the outcome. Their recommendations included clearer proposal language, stronger messaging and message distribution, and better outreach to religious organizations.

Though exit polls showed followers of no major religion were completely in agreement on the matter and some prominent Catholics held views in opposition to those of the church, funding was clearly cut along such ideological lines. The state’s seven Catholic dioceses’ contribution to the anti-same-sex-marriage effort accounted for over one-third of all funds in the campaign. The writers of the report note that embedding progressive religious voices will be paramount for future campaigns’ success and that the message of marriage equality must be framed both within individual faiths and in a mainstream way that will appeal to broader audiences.

Michigan took a few steps back in the fall of 2004, but if leaders learn from that experience and coordinate the type of campaign that rallies all in Michigan who truly believe in freedom and equality, the state might just take a leap forward.