A San Francisco man whose writings linked homosexuality to pedophilia and prostitution took center stage Thursday in the trial over California’s ban on same-sex marriage, with supporters and opponents of Proposition 8 disputing his role in the campaign.

William Tam, director of the Traditional Family Coalition, was one of five official proponents of Prop. 8, the November 2008 initiative that amended the state Constitution to define marriage as the union of a man and a woman.

Plaintiffs challenging the measure hope to use his incendiary statements to show that Prop. 8, promoted as a reaffirmation of traditional marriage, was based on anti-gay prejudice and stereotypes and was therefore unconstitutional.

In a message to supporters during the campaign, for example, Tam wrote that “other states would fall into Satan’s hand” if same-sex marriage remained legal in California. San Francisco’s government, “under the rule of homosexuals,” would next move to legalize sex with children and prostitution, he said.

Read the rest of Bob Egelko’s San Francisco Chronicle article here.