Jon Huntsman Regrets Nothing
Money quote in an interview with the New York Times Magazine. (Question is bolded. Huntsman's reply is not.)
Republicans couldn’t get over the fact that after you resigned as ambassador to China, you sent the president a thank-you note, referring to him as “a remarkable leader.”
I wrote the note, and I’d write it again.
The story about the letters can be read at the Daily Caller.