What do Messrs. Stewart and Huntsman have in common, apart from spelling their first name Jon? Apparently an interest in Asian language. Stewart puts the needle effectively in Huntsman for using Mandarin on the campaign trail, starting at time 5:00 of this clip. (Take-home message: If you're running in a political primary, don't speak in a language most of your audience can't understand.) Then at the end of the segment Stewart does a surprisingly creditable job of a Mandarin riff himself.
When you live in a "hard-language" environment, it can get really tedious hearing the fine-distinctions preening among foreigners about who has better command of the local language than someone else. This is despite the fact that they all may be quite good in it -- and that any ordinary person in that "hard" language country grows up with native linguistic command and no one gets excited by that achievement.
I will avoid such disputes in the case of Huntsman by saying (a) he can speak Chinese way better than I ever will and (b) I can understand him, in Chinese, much more easily than I can understand a normal Chinese person, in keeping with the theme I explored at length last year. That theme was: for non-native speakers of a language, why it's so much easier to understand other non-natives than people who grew up speaking the language. In the part I understand of the clip above, Huntsman is explaining how he learned Chinese during his years in Taiwan, and after a while he felt 不错 at it, bu cuo, "not bad." (Plus how he was the only US governor to speak Chinese, and what it was like to go with Reagan to China etc.)