Utah’s ban on same-sex marriages violates a fundamental right to marry protected by the US Constitution, a federal appeals court ruled Wednesday.

The 2-to-1 decision marks the most important judicial ruling yet among a steady stream of court decisions that in the past year have invalidated state laws banning same-sex marriages or recognition of such marriages performed in other states.

The decision was issued on the same day that a federal judge in Indiana struck down that state’s ban on same-sex marriage, becoming the 10th federal judge to invalidate a state ban in the past six months.

Taken together, Wednesday’s decisions give even greater momentum to gay rights activists seeking an eventual decision at the US Supreme Court mandating same-sex marriage be made legal coast-to-coast.

“A prime part of the history of our Constitution … is the story of the extension of constitutional rights and protections to people once ignored or excluded,” Circuit Judge Carlos Lucero wrote in the 10th Circuit decision, quoting a 1996 US Supreme Court case.

“Consistent with our constitutional tradition of recognizing the liberty of those previously excluded, we conclude that [gay and lesbian] plaintiffs possess a fundamental right to marry and to have their marriages recognized,” he wrote in an opinion joined by Judge Jerome Holmes.

In a dissent, Judge Paul Kelly criticized the majority for deciding an important issue of constitutional law without waiting for clear guidance from the US Supreme Court.

“We should resist the temptation to become philosopher-kings, imposing our views under the guise of constitutional interpretation of the Fourteenth Amendment,” he said.

The appeals court said it would maintain an existing stay on the case until the legal dispute was resolved.

The 65-page decision and 21-page dissent were handed down on the eve of the one-year anniversary of the Supreme Court’s decision in US v. Windsor, striking down the federal Defense of Marriage Act.

The action at the Denver-based Tenth US Circuit Court of Appeals sets the stage for an expected appeal by Utah officials to the Supreme Court and a potential constitutional showdown over same-sex marriage.

It is the first of what may become several appeals court decisions likely to rise to the high court. Those cases will give the justices an opportunity to rule whether there is a fundamental right to marry regardless of sexual orientation or whether it will remain up to the states to define marriage.

The same Tenth Circuit panel also heard an appeal filed after a federal judge in Oklahoma struck down that state’s ban on same-sex marriages. A decision in that case is pending.

In addition, a decision is also pending from a panel of the Third Circuit in Richmond concerning the constitutionality of Virginia’s ban on same-sex marriage.

In the Utah case, the appeals court found that because the right to marry is a fundamental right under the Constitution, the state would have to overcome the strictest judicial scrutiny to justify its ban on same-sex marriage.

Utah officials had argued that the state’s definition of marriage was intended to advance state interests in fostering a culture of child-centric marriage in which children would be conceived and raised by their married biological mother and father together in the same home.

The state also argued that retaining the existing definition of marriage was necessary to avoid civic strife and a threat to religious freedom.

Judge Lucero said none of the rationales satisfied the requisite level of scrutiny.

“Several recent district court decisions have rejected nearly identical state attempts to justify same-sex marriage bans based on procreative concerns,” he said.

He added: “A state’s interest in developing and sustaining committed relationships between childbearing couples is simply not connected to its recognition of same-sex marriages.” Lucero said the court could not imagine a scenario in which recognizing same-sex marriages would affect the decision of an opposite-sex couple to have a child, marry, or stay married.

Instead of ripping the institution apart, adding new couples to the ranks of the married would help sustain it and build it up, he said.

“Rather than being mutually exclusive of the procreative potential of marriage, these freedoms – to choose one’s spouse, to decide whether to conceive or adopt a child, to publicly proclaim an enduring commitment to remain together through thick and thin – reinforce the childrearing family structure,” the judge wrote.

“Such freedoms support the dignity of each person,” he said.

Lucero rejected state arguments that judges should respect democratic decision-making, such as the 66 percent of Utah voters who approved the state’s one-man, one-woman definition of marriage. He also swept aside arguments that the court should recognize that under the nation’s system of federalism it has traditionally been within the authority of the states to regulate marriage.

“As a matter of policy, it might be preferable to allow the national debate on same-sex marriage to play out through legislative and democratic channels,” he said.

“But the judiciary is not empowered to pick and choose the timing of its decisions,” Lucero said.

He added: “The protection and exercise of fundamental rights are not matters for opinion polls or the ballot box.”

In his dissent, Judge Kelly said the regulation of marriage is a power reserved to the states and that the State of Utah had offered a rational and acceptable justification for retaining its traditional definition of marriage.

“While the court has recognized a fundamental right to marriage, every decision vindicating that right has involved two persons of the opposite gender,” he said.

“If the states are the laboratories of democracy, requiring every state to recognize same-gender unions – contrary to the views of its electorate and representatives – turns the notion of a limited national government on its head,” the judge said.

Kelly said key portions of Lucero’s decision involved areas of the law upon which the Supreme Court had not yet ruled.

“At best, the developments relied upon are ambiguous and certainly do not compel the conclusion that the Supreme Court will interpret the Fourteenth Amendment to require every state to extend marriage to same-gender couples, regardless of contrary state law,” he wrote.

He said the appeals court was misreading the Supreme Court’s Windsor decision. “Windsor did not create a fundamental right to same-gender marriage,” he said.

“To the contrary, Windsor recognized the authority of the states to redefine marriage and stressed the need for popular consensus in making such change.”

The case is Kitchen v. Herbert (13-4178).