I'd call Newt an intellectual who's lacking in conviction and integrity. I respect him as an intelligent man, but at the same time he's shown that he'll change what he says he believes to fit in with what he thinks you want to hear. I've seen Newt be so very many different people. Right now he's being Newt the anti-establishment outsider. Since I don't believe he actually changes his core beliefs, only his outward appearance, he comes off to me as slimy and devious.
I have this complaint about lots of politicians; Newt is not unusual. I wish they'd just clearly state what they believe and what they plan to do, so we could actually make an intelligent choice and vote for someone who actually might do the things they say. Instead we have people trying to appeal to everyone, even the voters that know they won't actually represent and the voters they plan to actively work against.