2 same-sex marriage bans lifted

• NEW: Court says same-sex marriage bans violate equal protection rights


• NEW: Plaintiff says she feels like her family can feel "legally secure"


• NEW: Decision is part of a trend overturning bans, but another circuit may soon uphold them


• NEW: If circuit courts issue different decisions, the Supreme Court may get back in the mix

Washington (CNN) -- Add Nevada and Idaho to the rapidly growing list of states to have their same-sex marriage bans tossed out in definitive fashion.

A ruling by a federal appeals court Tuesday adds further momentum -- and a degree of inevitably -- to the idea of a civil marriage for gays and lesbians becoming a reality in a majority of U.S. states.

Three judges from the 9th Circuit U.S. Court of Appeals in California concluded the bans in the two Western states violated the equal protection rights of same-sex couples to legally marry.

"The lessons of our constitutional history are clear: inclusion strengthens, rather than weakens, our most important institutions," said the judges. "When same-sex couples are married, just as when opposite-sex couples are married, they serve as models of loving commitment to all."

The decision comes after the Supreme Court on Monday let stand rulings striking down bans in five states and affecting similar laws in six others.

That means that in coming weeks, 32 states could allow same-sex marriage, an increase of 13 states since the beginning of the month.

Colorado and Utah announced Tuesday they would order county clerks to begin issuing marriage licenses to same-sex couples.

The decisions affecting Idaho and Nevada become the fourth such federal appeals court action to strike down voter-approved bans.

One of the original Idaho plaintiffs cheered the decision.

"It means so much for the courts to recognize our family and say that we must be treated equally," said Lori Watsen, who wed Sharene Watsen in New York in 2011. Their home state does not recognize their legal union. "Our son will be able to grow up in a world where the state treats his family the same as other families. Today's ruling means that we can finally have the same legal protections as other married couples and the security of knowing that our family is legally secure."

But advocates on both sides of the issue are waiting to see what a federal appeals court in Cincinnati will decide on bans in Kentucky, Michigan, Ohio and Tennessee.

Oral arguments by a judicial panel in August by the 6th Circuit suggested those bans may be upheld, in contrast to a nationwide trend over the past 15 months. A ruling there is expected any day.

A potential "circuit split" may prove the impetus for the U.S. Supreme Court to ultimately decide whether same-sex couples nationwide have a constitutional right to tie the knot.

By refusing to get involved now, the justices this week let stand appeals court rulings that immediately opened up the right to those in Indiana, Oklahoma, Utah, Virginia and Wisconsin.

Because neighboring states are covered by the appeals court's jurisdiction, same-sex marriage could be extended in coming weeks to Kansas, North Carolina, South Carolina, West Virginia and Wyoming.

The high court's deliberate move to stand off to the side may indicate its natural instincts to go slowly -- to allow hot-button issues like his one to develop on their own, without interference from nine unelected justices.

But the individual members of the bench may have also done some internal head counting and concluded with a shaky 5-4 conservative-liberal divide -- and moderate-conservative Anthony Kennedy the potential swing vote -- the final outcome was too uncertain to put same-sex marriage on the docket now.

The cases in the 9th Circuit Court's decision are Sevcik v. Sandoval (12-17668) in Nevada and Latta v. Otter (14-35420) in Idaho.