Mitt Romney's national security spokesman resigned Tuesday after critics questioned his conservatism because he is gay.
Richard Grenell announced he had decided to leave Romney's campaign shortly after he was hired in late April. Grenell, who is openly gay, previously worked for neoconservative former United Nations Ambassador John Bolton, as well as other foreign policy hawks.
"My ability to speak clearly and forcefully on the issues has been greatly diminished by the hyperpartisan discussion of personal issues that sometimes comes from a presidential campaign," Grenell said in a prepared statement.
Romney campaign manager Matt Rhoades said the campaign was disappointed with Grenell's decision, saying he "had superior qualifications for the position he was hired to fill."
A series of critics on the right had suggested Grenell's sexuality would present problems for the Romney campaign. Romney has struggled to court the religious wing of the Republican Party as he sought the nomination, having previously changed his position on social issues such as abortion.
Meanwhile, Romney on Tuesday accused President Obama of politicizing the death of Osama bin Laden a year ago but said it was "totally appropriate" for him to claim credit for ordering the U.S. military raid that ended with the terrorist leader's death in a hideout in Pakistan.
Obama's re-election campaign has used his decision to suggest that Romney would not have made the same call. Romney, the president's all-but-certain Republican challenger in the fall election, says he would have.
Marking the anniversary at a New York City fire house that lost 11 men on Sept. 11, 2001, Romney said he understood the president's desire to take credit for killing one of the world's most wanted men.
"It's totally appropriate for the president to express to the American people the view that he has that he had an important role in taking out Osama bin Laden," Romney said after visiting the lower Manhattan fire station with Rudy Giuliani, who was mayor when terrorists flew planes into the World Trade Center's twin towers and killed nearly 3,000 people.
"I think politicizing it and trying to draw a distinction between himself and myself was an inappropriate use of the very important event that brought America together," Romney said.
He and Giuliani had just eaten pizza with several firefighters.
Romney insisted that he would have ordered the strike on bin Laden's hideout in Pakistan.
"This is a person who had done terrible harm to America and who represented a continuing threat to civilized people throughout the world," Romney said, echoing his comments from a day earlier. "Had I been president of the United States, I would have made the same decision."
Giuliani, a former Romney rival and critic who since has endorsed the former Massachusetts governor's bid, also said Obama shouldn't use the anniversary to attack Romney.
"If he wants to take credit for it I have no problem with that at all. I wish he wouldn't use it as a source of negative campaigning. I think that's a big mistake," he said.