Behind Richard Grenell's Departure, a Right-Wing Storm It was the biggest moment yet for Mitt Romney's foreign policy team: a conference call last Thursday, dialed into by dozens of news outlets from around the globe, to dissect and denounce President's Obama record on national security. But Richard Grenell, the political strategist who had set up the call and was specifically hired to oversee such communications, was conspicuously absent, or so everyone thought. It turned out he was at home in Los Angeles, listening in, but stone silent and seething. A few minutes earlier, a senior Romney aide had delivered an unexpected directive, according to several people involved in the call. "Ric," said Alex Wong, a policy aide, "the campaign has requested that you not speak on this call." Mr. Wong added, "It's best to lay low for now." For Mr. Grenell, the message was clear: he had become radioactive. It was the climax of an unexpectedly messy and public dispute over the role and reputation of Mr. Grenell, a gay foreign policy expert known for his support of same-sex marriage, his testy relationship with the news media and his acerbic Twitter postings on everything from Rachel Maddow's femininity to how Callista Gingrich "snaps on" her hair. From his hiring three weeks ago, which prompted an outcry from some Christian conservatives, it became clear that the appointment of Mr. Grenell, a former Bush administration official with seemingly pristine Republican credentials, had become entangled in the unforgiving churn of election-year politics, leading to his resignation on Tuesday and the Republican candidate's first public misstep since effectively clinching the nomination. On one level, Mr. Grenell's short-lived and rocky tenure as Mr. Romney's foreign policy spokesman is the story of how halting attempts by the campaign to manage its relationship with the most conservative quarter of the Republican Party left an aide feeling badly marginalized and ostracized. But according to interviews with more than a dozen aides and advisers, it is also about how a fast-growing campaign, operating under the sharp glare of a general election, failed to spot the potential hazards of a high-profile appointment. Aides to Mr. Romney insist they did everything they could to keep Mr. Grenell from resigning, sending the campaign's highest-level officials to try to persuade him that they valued his expertise and that the matter would soon die down. In the end, they said, he chafed at the limitations of a disciplined presidential campaign. But those close to Mr. Grenell, known as Ric, insist that when he had sought forceful support from those who had entrusted him with a major role, the campaign seemed to be focused, instead, on quieting a political storm that could detract from Mr. Romney's message and his appeal to a crucial constituency. "It's not that the campaign cared whether Ric Grenell was gay," one Republican adviser to the campaign said. They believed this was a nonissue. But they didn't want to confront the religious right. Like many interviewed, this adviser insisted on anonymity to discuss internal deliberations. Mr. Grenell, a 45-year-old with a sharp wit, had joined the Romney campaign in April with sterling recommendations from Bush-era foreign policy figures, and an impressive résumé. He had served as a United States spokesman at the United Nations under four ambassadors during the Bush administration. Rich Williamson, a senior diplomat under several Republican presidents, and John R. Bolton, the former United States ambassador to the United Nations, had both urged his appointment. In mid-April, Mr. Grenell sailed through an interview with Eric Fehrnstrom, Mr. Romney's senior adviser, and Gail Gitcho, his communications director. But before he left the Romney headquarters, he felt compelled to say that he is gay. "It could be an issue," he volunteered. "It's not an issue for us," Mr. Fehrnstrom replied firmly. The campaign called around to Mr. Grenell's colleagues, seeking references, but as the warm reviews flowed in, a campaign known for its no-stone-unturned meticulousness overlooked his electronic footprints: namely, dozens of cutting Twitter postings. One swipe at Newt Gingrich's weight, for example, went like this: "I wonder if newt has investments in Lipitor." Mr. Grenell trumpeted his new position in a message to friends on April 19. He signed the note, "My next adventure." He made preparations to move from Los Angeles. Within days, stories about Mr. Grenell's Twitter feed surfaced, prompting him to delete more than 800 posts. Mr. Grenell apologized for what he called "hurtful" comments, but the campaign privately dismissed the issue. Jeff Zeleny and Richard A. Oppel Jr. contributed reporting from Washington.