Three states are continuing their legal fight against same-sex marriage, despite rulings from federal appeals courts that oversee those states that concluded gay and lesbian couples have the right to marry.

Even as officials in other states have abandoned defense of gay marriage bans, Kansas, Montana and South Carolina are refusing to allow same-sex couples to obtain marriage licenses without a court order directing them to do so. It could be another month or more before the matter is settled.

In a political campaign debate Monday, Kansas Gov. Sam Brownback vowed to defend his state's constitutional amendment defining marriage as between a man and a woman. A federal court hearing is scheduled for Friday.

There seems little doubt that U.S. District Judge Daniel Crabtree ultimately will set aside the state's gay marriage ban. That's because the 10th U.S. Circuit Court of Appeals, encompassing Kansas and five other states, has said a state may not deny a marriage license to two people of the same sex.

"He is absolutely bound and has to make that decision," said Sarah Warbelow, legal director of the Human Rights Campaign.

The same requirement holds true for federal judges who are hearing same-sex marriage lawsuits in Montana and South Carolina.

John Eastman, chairman of the anti-gay marriage National Organization for Marriage, agreed with Warbelow that federal judges almost certainly will rule to allow same-sex marriages. But Eastman urged state officials to continue to put up a legal fight until the Supreme Court decides the issue one way or the other.

"Until the Supreme Court decides it, this remains a viable option," Eastman said.