These Huntsman people are the same breed who urged the GOP to nominate Ford or Howard Baker instead of Ronald Reagan in 1980. I wouldn't put much stock in what they have to say.
Most people thought of Reagan as a dumb extremist like Palin until the debate with Carter. He would never have won in a landslide without that. Palin has not proven herself to be intelligent yet.
Ronald Reagan moderated his rhetoric, as did Barack Obama. Sarah Palin didn't. That makes all the difference in the world. Reagan never proved that he was a rocket scientist, not that such is necessary for the Presidency. Failing to moderate her rhetoric, indeed becoming decisive, Sarah Palin showed that she was unsuited to being one stoke or heart attack away from the Presidency.