White House press secretary Jay Carney said the White House wouldn't be commenting on the court's rejection of California's same-sex marriage ban, saying that the administration doesn't weigh in on ongoing litigation.
But the president's top spokesman also seemed to suggest an endorsement of the decision, without saying so.
"He has long opposed divisive and discriminatory efforts to deny rights and benefits to same-sex couples," Carney added.
The reaction is typical for a president who has acknowledged grappling with the issue. The president opposed gay marriage in the 2008 campaign, but has since said his opinion is "evolving."
Last year, his administration dropped its legal defense of the federal law defining marriage as "a legal union between one man and one woman." The president also called for the repeal of the Clinton-era law. Such moves have led some to surmise that the president is evolving in the direction of a public endorsement for same-sex marriage.
That endorsement didn't arrive Tuesday. Carney told reporters the president's personal stance has not changed.
The reaction of Republican presidential hopefuls was more predictable.
The front-runner, former Massachusetts Gov. Mitt Romney, said in a prepared statement that "unelected judges cast aside the will of the people of California."
"This decision does not end this fight, and I expect it to go to the Supreme Court. That prospect underscores the vital importance of this election and the movement to preserve our values," he said.
Romney added that he would, as president, "appoint judges who interpret the Constitution as it is written and not according to their own politics and prejudices."
Former House Speaker Newt Gingrich said the ruling is exposing more Americans "to the radical overreach of federal judges and their continued assault on the Judeo-Christian foundations of the United States."
"Should the Supreme Court fail to heed the disastrous lessons if its own history and attempt to impose its will on the marriage debate in this country by affirming today's 9th Circuit decision, it will bear the burden of igniting a constitutional crisis of the first order," he said.
Michael A. Memoli contributed to this report.