http://www.slate.com/articles/news_and_politics/politics/2012/11/gay_marriage_votes_and_andrew_sullivan_his_landmark_1989_essay_making_a.html

In 1989, most Americans had never even heard of gay marriage, and certainly couldn’t conceive that it would one day be legalized by popular vote. That year, Andrew Sullivan wrote a landmark essay for the New Republic, “Here Comes the Groom: A (Conservative) Case for Gay Marriage.” Sullivan’s essay is one of the most important magazine articles of recent decades. His argument, which he went on to elaborate in his books Virtually Normal and Same-Sex Marriage and in later essays, is that marriage for gays would “foster social cohesion, emotional security, and economic prudence.” Sullivan’s conservative case would eventually become the intellectual and moral foundation of the campaigns to legalize gay marriage. Sullivan gave Slate permission to reprint his New Republic essay in full.