Virginia has become the latest state to have its ban on same-sex marriage declared unconstitutional.

Late Thursday, US District Judge Arenda Wright Allen announced that the state’s constitutional amendment restricting marriage to one man and one woman violated the fundamental right of gay men and lesbians to marry.

The 41-page ruling came only nine days after Judge Allen heard arguments in the case. Her decision is similar to recent rulings issued by federal judges in Utah and Oklahoma striking down same-sex marriage bans in those states.

Allen stayed her decision pending the outcome of an expected appeal to the Fourth US Circuit Court of Appeals in Richmond, Va. As a result, no gay couples in Virginia will be able to marry at least until the appellate court acts.

“The Court is compelled to conclude that Virginia’s Marriage Laws unconstitutionally deny Virginia’s gay and lesbian citizens the fundamental freedom to choose to marry,” she wrote in her decision. “Government interests in perpetuating traditions, shielding state matters from federal interference, and favoring one model of parenting over others must yield to this country’s cherished protections that ensure the exercise of the private choices of individual citizens regarding love and marriage.”

The decision in Virginia is the latest in a growing number of legal victories by gay rights activists and lawyers who have launched a nationwide blitz of litigation.

Earlier this week, a federal judge in Kentucky struck down a state law that barred recognition of same-sex marriages performed in other states, and in Nevada the state attorney general announced that she would no longer defend that state’s ban on same-sex marriages.

“The bipartisan momentum for marriage is building at an unprecedented speed,” Evan Wolfson, president of Freedom to Marry, said in a statement after the Virginia decision was announced.

“There has been a fundamental shift in the legal landscape,” he said. “America is ready for the freedom to marry and those couples in Virginia, on the eve of Valentine’s Day, are ready to marry.”

Seventeen states and the District of Columbia recognize same-sex marriages. In contrast, more than 30 states have constitutional amendments or statutes that define marriage as a union between one man and one woman.

Public opinion polls suggest that opposition to same-sex marriage is decreasing and support for it is increasing. But the current legal strategy of gay rights groups is not aimed at winning votes at the state level. It is instead aimed at persuading judges to order objecting states to jettison their restrictions.

It remains unclear to what extent the recent judicial decisions reflect a substantial change of legal landscape. Each of the three federal judges who have invalidated state same-sex marriage bans was appointed by a Democratic president – two by President Obama and one by President Bill Clinton.

All three decisions are united in their conclusion that the US Supreme Court’s landmark ruling last June invalidating the federal Defense of Marriage Act (DOMA) points inexorably to the conclusion that a majority of justices believe there is a fundamental right protected by the US Constitution for same-sex couples to marry.

If the justices recognize such a right, the high court took great pains last June to avoid announcing it.

Nonetheless, Judge Allen points to a single paragraph in the DOMA decision that she says telegraphs the high court’s recognition of a fundamental right to gay marriage.

For support, she cites the same conclusion reached by the federal judge who struck down Oklahoma's same-sex ban. He called that section of the DOMA decision “a disclaimer of enormous proportion.”

If they are correct that five of the high court’s nine justices recognize a fundamental right to marriage regardless of gender, such a decision would be a landmark civil rights ruling. But it remains unclear whether the court is prepared to issue such a ruling.

On the other side of the debate are those who argue that the authority to decide who can marry is within the power of the states to determine. If the authority belongs to the states, then state statutes and constitutional bans would stand – at least until they were challenged at the polls by a majority of voters.

Allen, in her decision, rejected the argument that judges should allow the political process to resolve tough social issues such as same-sex marriage. Proponents of such an approach say the political process can work in ways that foster compromise and broader acceptance.

“The proposal disregards the gravity of the ongoing significant harm being inflicted upon Virginia’s gay and lesbian citizens,” she wrote. “When core civil rights are at stake the judiciary must act.”

Gay rights supporters hailed the Virginia decision as another step forward. “The steady march toward equality continues today with this historic decision,” Joshua Block, a staff attorney with the ACLU Lesbian Gay Bisexual and Transgender Project, said in a statement. “Support for the freedom to marry has seen an amazing increase in the past few years, and we will continue to work to ensure that all couples have access to the dignity and protection that only comes with marriage.”

Advocates of the traditional view of marriage denounced Allen’s decision.

“This is another example of an Obama-appointed judge twisting the Constitution and the rule of law to impose her own views of marriage in defiance of the people of Virginia,” Brian Brown, president of the National Organization for Marriage, said in a statement.

“The US Supreme Court has said that states have the preeminent duty of defining marriage,” he said. “The people of Virginia did just that in voting overwhelmingly to affirm marriage as the union of one man and woman.”

“That decision should be respected by federal judges and we hope the US Supreme Court ends up reversing this terrible decision,” Mr. Brown said.

Allen’s decision stems from a lawsuit filed on behalf of two same-sex couples. Timothy Bostic and Tony London have been together for 25 years. The Norfolk, Va., couple want to get married, but were denied a license.

Carol Schall and Mary Townley live in Chesterfield County. They have been together nearly 30 years and were legally married in California in 2008. They sued to gain equal recognition of their marriage and to require Virginia officials to treat them equally with other married couples in the state.

The case is Bostic v. Rainey (13CV395).