Richard Grenell, presumptive GOP presidential nominee Mitt Romney's controversial choice for national security spokesman, is leaving the campaign less than two weeks after his appointment.

The Washington Post's Jennifer Rubin, who broke the news Tuesday, suggested that the openly gay Grenell, a former George W. Bush administration official, likely resigned because of a "full-court press by anti-gay conservatives." Grenell confirmed his resignation in a statement to Rubin:

I have decided to resign from the Romney campaign as the Foreign Policy and National Security Spokesman. While I welcomed the challenge to confront President Obama’s foreign policy failures and weak leadership on the world stage, my ability to speak clearly and forcefully on the issues has been greatly diminished by the hyper-partisan discussion of personal issues that sometimes comes from a presidential campaign. I want to thank Governor Romney for his belief in me and my abilities and his clear message to me that being openly gay was a non-issue for him and his team.

The Huffington Post recently reported that days after joining the campaign and coming under fire for numerous sexist and impolitic statements he had made about prominent women and members of the media, Grenell scrubbed over 800 tweets from his Twitter feed and deleted his personal website.

Rubin didn't mention Grenell's controversial statements in her post about his resignation.

Grenell drew harsh criticism from reporters during his tenure as a spokesman for the United Nations. Former Reuters reporter Irwin Arieff told HuffPost that Grenell "often lied," adding that he was the "most dishonest and deceptive press person" he'd worked with in over two decades on the job.

“We are disappointed that Ric decided to resign from the campaign for his own personal reasons," Romney campaign manager Matt Rhoades said in a statement. "We wanted him to stay because he had superior qualifications for the position he was hired to fill.”

Jimmy LaSalvia, the co-founder and executive director of conservative pro-gay rights group GOProud, called Grenell's resignation a "sad day in America." LaSalvia stressed that he hadn't been briefed on the grounds for his departure, but said that the message it sent was a bad one.

"The best and brightest aren't able to do their jobs because a few on the fringe are so fascinated with their personal lives and make such an issue out of it that they are forced to leave their jobs," he said. "On a day that national security affairs are front and center, Mitt Romney doesn't have the best person out there speaking for him, and he has Bryan Fischer [of the American Family Association] and Tony Perkins [of the Family Research Council] to thank for that."

R. Clarke Cooper, executive director of the Log Cabin Republicans, also released a statement:

Ric made the choice that he feels is best for the Romney campaign, and I respect his decision. It is unfortunate that while the Romney campaign made it clear that Grenell being an openly gay man was a non-issue for the governor and his team, the hyper-partisan discussion of issues unrelated to Ric's national security qualifications threatened to compromise his effectiveness on the campaign trail. As a Bush Administration colleague of Ric, I can attest to his experience and qualifications in the national security portfolio. Ric was essentially hounded by the far right and far left. The Romney campaign has lost a well-known advocate of conservative ideas and a talented spokesman, and I am certain he will remain an active voice for a confident U.S. foreign policy.

UPDATE: 5:15 p.m. -- Hours after Grenell's resignation was announced, competing stories emerged as to what had caused it. The initial report suggested that pressure from social conservatives had forced Romney's hand. But that same report, written by the Post's Rubin, later clarified that aides to Romney had urged Grenell to stay. He left, the piece added, in part because he hadn't come on board at a time when foreign policy issues were dominating the campaign.

For Democrats, of course, the former storyline is better than the latter. When news of Grenell's resignation broke, the Obama campaign's digital director, Teddy Goff, immediately tweeted, "Today we learned that in the year 2012, a Republican nominee for President can't have a gay person as spokesman."

And an official close to the Obama campaign, who would speak only on condition of anonymity, offered the following: "This just shows that Romney can't have a clean Etch A Sketch moment. He is stuck where he is in the far right corner of the world."

The reality, however, may be more complicated than that. As Politico's Maggie Haberman noted: "[I] do believe Romney folks tried to get Grenell to stay. Don't think they wanted the headline they got."

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