WASHINGTON — President Obama’s election-year vagueness on gay marriage is coming under fresh scrutiny.

Education Secretary Arne Duncan broke ranks with the White House on Monday, stating his unequivocal support for same-sex marriage one day after Vice President Joe Biden suggested that he supported gay marriage as well.

Obama aides worked to manage any political fallout. They said the back-to-back remarks by two top administration officials represented personal viewpoints and were not part of an effort to lay groundwork for a shift in the president’s position.

Obama aides also tried to use the latest flare-up in the gay-marriage debate to shine a light on GOP rival Mitt Romney’s history of equivocating on some gay-rights issues, an attempt to turn a potential political problem into an opportunity.

Obama, who supports most gay rights, has stopped short of backing gay marriage.

Without clarification, he has said for the past year and a half that his personal views on the matter are “evolving.”

The White House held firm Monday to that position, which polls show puts the president increasingly at odds with his party and the majority of Americans on gay marriage.

Throughout his first term, he has sought to walk a fine line on same-sex marriage.

He’s trying to satisfy rank-and-file Democrats by supporting a range of gay rights issues without alienating crucial independent voters who could be turned off by the emotional social issue.

The president’s aides acknowledge his position can be confusing. In states where gay marriage is legal, the president says married gay couples should have the same rights as married straight couples.

But he does not publicly support the right of gay couples to enter into a marriage in the first place.

Romney favors a constitutional amendment to ban gay marriage.