Washington ? With a reach across the political divide for Utah Gov. Jon Huntsman as ambassador to China, President Barack Obama may have sidelined for now a potentially formidable Republican moderate and possible White House challenger in 2012.

Yet Huntsman, who has upset the GOP’s conservative base by supporting gay civil unions, may gain, too. The appointment, which requires Senate approval, gives him a chance to burnish his credentials and position himself as a viable presidential contender in 2016, if Obama appears to be a strong candidate for a second term in 2012.

John Weaver, a one-time senior strategist for John McCain’s presidential campaign who now advises Huntsman, said the governor put country ahead of personal partisan interest. Huntsman was national co-chairman of McCain’s failed bid against Obama.

“It’s no more complicated than that, though it is so unusual in Washington everyone has to take a magnifying glass to it,” Weaver said after Obama introduced Huntsman in the White House Diplomatic Reception Room.

“He was asked by the president to serve in a major diplomatic post, in a mission with a country most important to our economy, in dealing with Iran, Pakistan and North Korea. Jon is uniquely qualified and thus you don’t turn your nation down,” Weaver said.

Obama said he knew Huntsman’s nomination “wouldn’t be the easiest decision to explain to some members of his party.” But Obama said Huntsman was “the kind of leader who always puts country ahead of party and is always willing to sacrifice on behalf of our nation.”

Elected to his second term in November, Huntsman said he wasn’t looking for a new job and didn’t expect “to be called into action” by McCain’s winning rival.

“But I grew up understanding that the most basic responsibility one has is service to country,” he said, standing with Obama as his family looked on. “When the president of the United States asks you to step up and serve in a capacity like this, that to me is the end of the conversation and the beginning of the obligation to rise to the challenge.”

Huntsman will be 56 in 2016, young enough to handle the rigors of a national political campaign. Republican strategists say serving as U.S. envoy to China — which Obama says will be critical to solving many world problems — will only improve Huntsman’s reputation.