MADISON, Wis. (AP) — An openly gay Milwaukee legislator has introduced a constitutional amendment that would repeal Wisconsin's gay marriage ban. Democratic Sen. Tim Carpenter unveiled the amendment in the state Capitol flanked by a gay couple from Madison and Rep. JoCasta Zamarripa, a bisexual Milwaukee Democrat. Carpenter said the state's ban makes Wisconsin an island, noting Minnesota, Iowa and Illinois have moved to allow same-sex marriages. Wisconsin's remaining 14 Democratic senators co-sponsored the legislation, which faces an uphill battle in the Republican-controlled Legislature. The proposal comes a week after the American Civil Liberties Union filed a lawsuit that also challenges the state's gay marriage law. Fifty-nine percent of voters passed the ban in 2006.