The Supreme Court on Monday allowed the Supreme Court of the United States to strike down a key provision of a controversial federal law that allows states to bar same-sex marriage and civil unions in cases of domestic violence.

The court on Monday ruled 4-3 in favor of a gay couple who argued that a state ban on same-gender marriage violates the U.S. Constitution’s equal protection clause.

The ruling was the latest twist in a long-running legal battle over the definition of “sexual orientation” and the role of marriage in protecting gay and lesbian Americans.

It could also set the stage for similar court cases challenging a law banning gay adoption in Utah.

In the case before the Supreme Courts, a married gay couple argued that the state’s ban on marriage equality violated their constitutional right to equal protection under the law.

The high court had already ruled last year that states cannot ban gay marriage.

The ruling could set up a new legal challenge to that ruling, which is already pending before the U,S.

Supreme Court.

But on Monday, Justice Elena Kagan wrote that she agreed with the lower court ruling that the states’ argument about marriage was “not persuasive.”

“The Court’s decision today is consistent with its recent holding that marriage is an essential component of a person’s dignity and worth,” Kagan said in a separate dissent.

“Indeed, marriage is the central institution of the American family and, in many ways, the lifeblood of the nation,” she continued.

“Marriage, in the view of the Court, has always been an institution central to the meaning and operation of the Bill of Rights.”

The Supreme Court had previously ruled that states could not ban gay adoption.

The lower court had found that the Constitution gives states the right to ban same-gendered marriage.

But the majority, joined by Chief Justice John Roberts, said that the court should strike down the law because it violated equal protection.

Justice Anthony Kennedy also dissented from the majority opinion.

The majority opinion is a rebuke to the gay rights movement, which has called the ban on gay marriage unconstitutional.

The Supreme Courts decisions on marriage and abortion have been split since 1973, with the court allowing a few states to ban abortion and same-Sex marriage, while striking down a majority of other bans.

The justices also struck down a law requiring public schools to teach about gender identity and a requirement that religious institutions provide contraceptive coverage.