SAN FRANCISCO AP – A Yale professor testifying in a case challenging California’s same-sex marriage ban said Tuesday that the 2008 campaign to pass Proposition 8 played on stereotypes historically used to portray “homosexuals as perverts who prey on young children, out to entice straight people into sick behavior.”

George Chauncey, a historian who specializes in the subject of 20th century gay life, was the second expert witness to appear for two couples unable to marry because of the state’s voter-approved gay marriage ban. Their lawsuit has led to the first federal trial to decide the constitutionality of laws limiting marriage to a man and a woman.