The Supreme Court rulings on same-sex marriage reverberated across the Potomac River and into Virginia on Wednesday, underscoring a split in the marquee governor’s race in a state that bans gay unions.

The decisions to deem a key element of the federal Defense of Marriage Act unconstitutional and decline on technical grounds to decide on California’s ban on gay marriage — allowing such marriages to resume there — appear to have no immediate impact on Virginia’s laws, experts said. But the rulings amplify an issue that has sharply divided the two leading candidates for governor, Attorney General Ken Cuccinelli II (R) and businessman Terry McAuliffe (D).

Cuccinelli has weighed in to keep the California law banning gay marriage in place. In 2010, he and attorneys general from 12 other states filed an amicus brief with a federal appeals court arguing that Proposition 8 should be allowed to stand. Cuccinelli joined a larger group of states in January to file another amicus brief with the Supreme Court in the case.

In both briefs, Cuccinelli and his allies argued that prohibiting a ban on gay marriage could open the door to legalizing polygamy, among other potential consequences.

Brian J. Gottstein, spokesman for the attorney general’s office, noted in a statement Wednesday that Virginians had “voted overwhelmingly” in 2006 to ban gay marriage.

“Today, the court’s two decisions on marriage make clear that the rulings have no effect on the Virginia Marriage Amendment or to any other Virginia law related to marriage,” Gottstein said. “Consistent with the duties of the attorney general, this office will continue to defend challenges to the constitution and the laws of Virginia.”

Like most Democrats, McAuliffe applauded the rulings — “because everyone should be treated equally.”

“While I support marriage equality, I understand that this is an issue that Virginians of goodwill come down on both sides of,” he said in a statement. “This decision moves our nation in the right direction, but there is more to be done to ensure we have equality for all.” And Cuccinelli, McAuliffe said, “has spent his career putting up walls around Virginia and telling gay Virginians that they’re not welcome.”

Cuccinelli opposes same-sex marriage and, more generally, gay rights. In a 2008 speech, he said: “When you look at the homosexual agenda, I cannot support something that I believe brings nothing but self-destruction, not only physically but of their soul.”

Cuccinelli also stirred controversy in 2010 when he advised Virginia colleges and universities that they could not adopt policies prohibiting discrimination based on sexual orientation without the General Assembly’s consent.

Although the same-sex marriage ban passed in 2006 with 57 percent support, public opinion has shifted markedly. In a Washington Post poll in May, 56 percent of Virginians said it should be legal for gay and lesbian couples to marry, up from 46 percent two years earlier.

“At some point, given the changing public opinion, I expect the Virginia marriage ban will be on the ballot for repeal,” predicted Carl Tobias, a University of Richmond law professor.

Tobias said the ruling striking down a key provision of DOMA “does not directly affect the Virginia ban” but could matter for Virginia same-sex couples who were married in states that permit such unions, because they could now receive federal benefits they had been denied by the law.

But James Parrish, executive director of the pro-gay-rights group Equality Virginia, said that for such couples in Virginia, “access to those federal marital protections is less clear and will require some work.” That’s because some federal benefits are based on where a couple’s marriage ceremony occurred and others are based on their residency.

In a statement, Victoria Cobb, president of the conservative Family Foundation of Virginia, called the decisions “a mixed bag for both sides. We’re certainly disappointed the Court struck down DOMA but the Court has allowed the decision that millions of Americans, and Virginians, have already made on the definition of marriage to stand.”

McAuliffe has said he supports gay marriage, but last week he would not say whether Virginia’s ban should be overturned. He said that because of the General Assembly’s Republican tilt, the ban is “not going to change during my four years as governor.”

Cuccinelli campaign manager Dave Rexrode said in a statement that Cuccinelli’s “consistency and clarity on this matter stands in stark contrast to Terry McAuliffe who is eager to attack the attorney general without taking a position himself.”