(CBS)--Mitt Romney's spokesman on foreign policy issues abruptly quit Tuesday after anti-gay conservatives made an issue of his outspoken support for gay marriage. Richard Grenell resigned on what was to be his first official day on the job, citing the "hyper-partisan discussion of personal issues."
Grenell, who is openly gay, was hired by the Romney campaign less than two weeks ago. He was a Republican communications strategist for over a decade, including a stint as the national security and foreign policy spokesman in the George W. Bush administration.
Some prominent conservatives criticized Grenell's role in Romney's campaign after he made comments via Twitter and other media in support of same-sex marriage. Last week, Matthew Franck wrote in the National Review, "I agree that Grenell's being openly gay is, in itself, of no consequence for his service in the Romney campaign. Nor is the fact that he supports same-sex marriage. ... But Grenell has made a particular crusade of the marriage issue, with a kind of unhinged devotion that suggests a man with questionable judgment."
In addition to the same-sex marriage issue, Grenell also often tweeted about prominent Democrats and rival presidential candidates, particularly former House Speaker Newt Gingrich and his wife, Callista. He dinged Callista about her hair style -- "do you think Callista's hair snaps on?" -- and Gingrich's about his first two marriages - "compliments all the wives, proving he can't pick just one first lady." Of Secretary of State Hillary Clinton, he tweeted, "Hillary is starting to look like Madeleine Albright."
In a statement to news outlets, Grenell explained his decision to resign, while thanking Romney for hiring him. He wrote:
"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."
Romney Campaign Manager Matt Rhoades said the camapign is "disappointed that Ric decided to resign from the campaign for his own personal reasons."
"We wanted him to stay because he had superior qualifications for the position he was hired to fill," he added.
A source close to the Romney campaign denied that Grenell resigned because of complaints he is gay. Rather, the source said, Grenell stepped down because he had become a story himself.