The American Civil Liberties Union says a U.S. District Court Judge has stricken down Missouri’s 2004 constitutional amendment banning gay marriage and has thrown out a 1996 law to bar Recorders of Deeds in Missouri from issuing marriage licenses to same-sex couples.

The ruling was handed down this morning in a case filed against Jackson County in June by the ACLU on behalf of two couples.

Judge Ortrie D. Smith ruled that the provision and the amendment discriminate against same-sex couples based on their sexual orientation and violate the Due Process Clause and the Equal Protection Clause of the U.S. Constitution.

In the decision, made available by the ACLU, Judge Smith writes, “The Court does not take lightly a request to declare that a state law is unconstitutional,” noting that the statute is passed by representatives of the people and the 2004 amendment was passed by voters themselves. “But it should not be forgotten,” he continues, “that the Constitution is also an expression of the people’s will. Indeed, it is the paramount expression of the people’s will; it cannot be easily cast aside or circumvented by a vote of the citizens of a single state.”

Judge Smith writes that the ruling does not deal with recognition of same-sex marriages from other states, but a Kansas City circuit judge ruled October 3 that Missouri must recognize those. Attorney General Chris Koster chose not to challenge that ruling.

Today’s ruling also follows that on Wednesday by a St. Louis judge that the state Constitution violates the rights of gay couples who want to marry. That has been followed by debate about whether it applies only in St. Louis or statewide. Attorney General Koster has appealed that ruling.

Groups who support same-sex marriage were quick to praise the latest ruling. A.J. Bockelman, executive director of PROMO, writes, “this is an incredible, historic day for Missouri. Missouri is now a state where all couples have the freedom to marry the person they love right in their home state.”

ACLU legal director Tony Rothert calls the day “historic for same-sex couples, who have waited far too long to be able to marry in Missouri. It feels great for Missouri to join the mainstream by allowing loving couples to formalize their commitment with marriage.”