A federal judge ruled Tuesday that Oklahoma’s ban on same-sex marriage is unconstitutional, the latest in a string of recent court decisions that have challenged such state prohibitions.

The decision by U.S. District Judge Terence Kern is stayed pending appeal, meaning marriages will not take place immediately in Oklahoma. On Jan. 6, the Supreme Court halted same-sex marriages in Utah, which had taken place over the course of 17 days after a federal judge there had ruled it was unconstitutional to bar gay and lesbian couples from marrying. Last month, the New Mexico Supreme Court decided unanimously to overturn that state’s ban on same-sex unions.

Two couples, Mary Bishop and Sharon Baldwin and Gay Phillips and Susan Barton, filed their case challenging Oklahoma’s ban in November 2004.

Kern referred to two previous Supreme Court decisions in his ruling. In 1996, in Romer v. Evans, the court struck down a Colorado constitutional amendment that forbade localities to pass laws protecting gays against discrimination, as some had done. Last June, in U.S. v. Windsor, the court struck down a key element of the Defense of Marriage Act and said the federal government must recognize same-sex marriages that are legal in the states where they were performed.

“There is no precise legal label for what has occurred in Supreme Court jurisprudence beginning with Romer in 1996 and culminating in Windsor in 2013, but this Court knows a rhetorical shift when it sees one,” Kern wrote.

Read the decision Federal judge strikes down Oklahoma same-sex marriage ban U.S. District Judge Terence Kern ruled the state's gay marriage ban violates the U.S. Constitution.

Gay rights advocates hailed the judge’s decision.

James Esseks, who directs the American Civil Liberties Union’s Lesbian Gay Bisexual Transgender & AIDS Project, said in an interview that the decision is “a reflection of how far we’ve moved on this issue.”

“This is not an issue for the coasts, this is not an issue just for the liberals,” he said. “This is increasingly America’s understanding of what marriage is, and fairness in marriage laws looks like.”

In a statement, Human Rights Campaign President Chad Griffin said that Kern, who was appointed by President Bill Clinton, “has come to the conclusion that so many have before him — that the fundamental equality of lesbian and gay couples is guaranteed by the United States Constitution. With last year’s historic decisions at the Supreme Court guiding the way, it is clear that we are on a path to full and equal citizenship for all lesbian, gay, bisexual and transgender Americans.”

But Brian S. Brown, president of the National Organization for Marriage, said in a statement that the Oklahoma decision “is the latest in a string of examples of the dangers posed to state marriage laws when the avenue of debate is the federal court system.”

To address these challenges, he added, the United States should pass a constitutional amendment “to protect marriage as the union of one man and one woman.”

Six months ago, the Supreme Court also let stand a lower court decision overturning California’s ban on gay marriage.

There are now more than 40 cases pending in state and federal courts that raise the question of whether banning same-sex marriages is constitutional, Esseks said, adding that he expects the issue to return to the nation’s highest court “within a couple of years.”

Oklahoma’s case falls under the jurisdiction of the U.S. Court of Appeals for the 10th Circuit, which has already set an expedited hearing for the Utah marriage case.

Robert Barnes contributed to this report.