Opponents and supporters of same-sex marriage dueled in federal court Wednesday over the question of whether anti-gay discrimination has largely faded or endures in ballot measures like California’s Proposition 8.

The third day of testimony in a lawsuit seeking to overthrow the November 2008 constitutional amendment reserving marriage for male-female unions highlighted a central dispute in the case: whether Prop. 8 was rooted in prejudice against a historically persecuted group.

The plaintiffs, two same-sex couples and the city of San Francisco, claim that the ballot measure, promoted as a restoration of traditional marriage, was a thinly veiled appeal to anti-gay bias. That argument, if successful, would make it easier for them to prove that Prop. 8 violates the constitutional guarantee of equal protection.

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