MADISON, Wis. -

U.S. Attorney James Santelle says the federal government is behind gay couples who are suing to have the right to marry.

The federal prosecutor for the Eastern District of Wisconsin spoke Monday at a rally in Milwaukee before gay couples and their supporters boarded a bus to Chicago, where arguments will be held Tuesday in Wisconsin's gay marriage case.

A federal judge overturned Wisconsin's ban on gay marriage in June. The state appealed that decision to the 7th Circuit U.S. Court of Appeals in Chicago.

Santelle is not involved in the lawsuit. But he says the couples' fight to have the same rights as opposite-couples "is what America is all about," and he is telling gay couples that "the federal government and the U.S. Department of Justice is with you."