Erick Erickson of RedState thinks that Jon Huntsman has disqualified himself from seeking the presidency by plotting a campaign while serving as ambassador to China: 

The reason I will never, ever support Jon Huntman is simple: While serving as the United States Ambassador to China, our greatest strategic adversary, Jon Huntsman began plotting to run against the President of the United States. This calls into question his loyalty not just to the President of the United States, but also his loyalty to his country over his own naked ambition. 

It’s not obvious to me that planning a presidential campaign while serving as an ambassador is necessarily disloyal. Unseemly and an indication of sheer careerism and ambition, yes. But disloyal? Although it’s not likely, it’s possible that Huntsman felt comfortable with the Obama administration’s policies on China and had no reservations executing those policies while believing that he could improve on Obama’ leadership in other areas.