MADISON, Wis. (AP) -

Wisconsin Attorney General J.B. Van Hollen says the U.S. Constitution's equal protection clause doesn't cover sexual orientation the same way it does gender discrimination and there's no fundamental right for gay couples to marry.

Van Hollen made his arguments in a brief filed Wednesday with a federal appeals court in Chicago.

He is asking the court to overturn a federal judge's decision declaring Wisconsin's ban on gay marriage unconstitutional.

Van Hollen said Wisconsin has always defined marriage as between a man and a woman and that was confirmed in 2006 when voters amended the state constitution to limit marriage to one man and one woman.

He said the case is really about whether a federal judge can rewrite state laws to create a new right for gay couples to marry.