It's wrong to use government force against homosexuals or treat them as second-class citizens.  Jesus never mentions the sin of homosexuality.  The apostle Paul makes it plain that homosexual tendencies, along with other temptations, should have been resisted: "Be not deceived; neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor abusers of themselves with mankind, nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners, shall inherit the kingdom of God." (1 Cor. 6:9-10). Then he immediately goes on to say that all these acts had been forgiven.
Jimmy Carter, Judge Not: Leaders of the Christian Right Have Injected Into America's Political Debate Some Divisive Religious Questions, The Atlanta Journal Constitution (Feb. 27, 1996), at http://www.cartercenter.org/news/documents/doc48.html.

Civil unions that allow a same-sex couple to visit each other in a hospital or transfer property to each other should be recognized by the State (but not marriage), based on the Sermon on the Mount [Matt. 7:1ff.], which is more central than an obscure passage in Romans [Rom. 1:26-27].
- Barack Obama, speech on March 2, 2008, at http://www.cbn.com/CBNnews/332110.aspx

Conservatives are fake Christians for opposing gay marriage because the Bible says don’t judge other people [Matt. 7:1] and to forgive [Matt. 6:12].
- Charles Barkley, interview on 2/17/08 on CNN with Wolf Blitzer at http://www.breitbart.tv/html/48184.html