Opponents of same-sex marriage could try to inject Thursday's California ruling into the presidential race by pointing to Sen. Barack Obama's unambiguous support for fully repealing the federal Defense of Marriage Act DOMA.
But California's decision is not likely to be taken up by presumptive Republican nominee Sen. John McCain as he tries to reach out to moderates and independents.
"I don't think [McCain's] going to talk about it that much," ABC News' George Stephanopoulos said on "World News With Charles Gibson."
Stephanopoulos observed that Obama's support for a repeal of DOMA and McCain's need for independent votes in the fall may make the ruling a "political wash" on the campaign trail as the two likely contenders engage in a "conspiracy of silence" on the controversial issue.
McCain raised neither the issue of gay marriage nor abortion in a speech Thursday outlining the objectives he would like to accomplish in a first term in the White House. But McCain's reluctance to raise such subjects may not be shared by all conservatives.
Offense Against the Defense of Marriage Act
While running for the Senate in 2004, Obama called DOMA. "an abhorrent law" and accused those in Congress who voted for it of having only been interested in "perpetuating division and affirming a wedge issue," according to a statement that he gave to the Windy City Times, a gay Chicago newspaper.
When he became a presidential candidate in 2007, Obama went on the record in a questionnaire for the Human Rights Campaign saying that he supports full repeal of DOMA.
Sen. Hillary Clinton, though, only supports repealing the portion of DOMA that blocks gays in state-recognized unions from receiving federal benefits. She would keep in place the part of DOMA that says a state does not have to recognize a same-sex marriage legally recognized in another state.
Part of the 1996 law, which was approved by former President Bill Clinton, stipulates that no state needs to recognize a marriage between people of the same sex even if it was legally recognized in another state.
In an interview with ABCNEWS.COM in last August, a former constitutional counsel to Presidents Ronald Reagan and George H.W. Bush previewed the conservative case that could be made against Obama's DOMA position.
"Certainly, I think it would be fair to say that it would be more likely for a court decision to impose the recognition of same-sex marriage from Massachusetts on another state in the event of the repeal of DOMA.," said Pepperdine law professor Douglas Kmiec.
More recently, Kmiec, who served as a legal adviser to Mitt Romney's losing campaign, has surprised some in the legal community by writing complimentary things about Obama's potential.
But the argument Kmiec laid out last year against Obama did not go unnoticed by the Illinois Democrat's campaign.
Harvard law professor Larry Tribe, who taught Obama constitutional law and serves as an informal adviser to his campaign, called ABC News after Kmiec's warning was first reported to argue that conservative concerns about same-sex marriage spreading by judicial fiat under Obama were unfounded.
"Marriage is not something that states have ever been obliged to recognize if it's been against their own public policy," said Tribe, who has testified on the subject before Congress. "Same-sex couples in Massachusetts are neither better nor worse off with DOMA repealed except that the repeal of DOMA is a way of telling that couple that their marriage in Massachusetts is not going to be made the subject of a symbolic and ineffectual slam by the federal government."
The public policy exception cited by Tribe is a well grounded one.
But by staking out a position on DOMA that is decidedly to the left of his Democratic presidential rival and to the left of the last Democratic president, Obama could open himself up to the charge that he is not taking all possible steps to block the spread of same-sex marriage by judicial fiat.
Referring to Clinton's support for partially repealing DOMA, Kmiec said last year, "Clinton's position is the more logically consistent position: If an individual is in a state-recognized same-sex marriage, they will not [under Clinton's approach] suffer any different treatment [from heterosexual couples] under existing federal law."
"Whereas Obama's position," Kmiec continued, "not only gives an endorsement to same-sex marriage in the context of federal law, it also makes it less likely -- not more likely -- that the states that favor traditional marriage will be displaced in their judgment."
Tribe rejected Kmiec's warning last year by arguing that a court that feels compelled to recognize a same-sex marriage conducted in another state can do so even with DOMA in place.
Referring to DOMA.'s relationship to the Constitution's Full Faith and Credit Clause, Tribe said, "a state that fits professor Kmiec's hypothetical would be a state that would not be influenced by Congress anyway, because an act of Congress is subordinate to the Constitution."