MILWAUKEE (AP) -

One Democratic candidate for Wisconsin attorney general is starting a petition calling on the Department of Justice to stop defending the state's constitutional ban on same-sex marriage.

Democratic Rep. Jon Richards, of Milwaukee, said Monday that he's for marriage equality and he believes Wisconsin's ban violates the U.S. constitution's equal protection clause. He says he won't defend it if elected attorney general.

He also has posted a petition on his campaign website, asking supporters to join him in asking the state Justice Department not to defend the ban.

Richards is running to replace Republican Attorney General J.B. Van Hollen, who is not seeking another term.

Two other Democrats and one Republican, Waukesha County District Attorney Brad Schimel, also are running.