Recall that the religious right has not only spent the past 30 or 40 years fighting to prevent gays and lesbians from marrying. They have also fought tooth and nail against every advance in civil rights that has come during that time, affecting employment discrimination, child custody, health care decision-making... you name it.
This is why the religious right lost the battle on gay marriage. They erroneously believed that the common American value system was their religious beliefs. It wasn't. Our nation's value system is a belief -- often inconsistently held, but one held nonetheless -- that individual rights and individual liberty matter.