This is a fair assessment before she was a candidate. The campaign proved that the assertion was incorrect. And to this day she is more relevant that most other republicans. Sarah Palin has single-handedly reshaped the argument... in one "twitter" post she nuked Obamacare. Got to love her style.
IF he said it, it sounds more to me like he meant the position of being thrown into the national scene as in the MEDIA on a campaign trail. And she was put through the ringer, as was her family. She handled it well, however. I read it to mean he was concerned about that, after meeting her, not that she wasn’t prepared to be VP.