It's CNN... They can get away with conducting polls for ridiculously unlikely scenarios. They call that news.
Its how they form people's opinions for them. As far as I know Palin isn't running either.
As long as they are putting people in there that aren't going to run, why not put Chris Christie in the poll. Oh thats right, he's a threat and not a RINO. Big media don't like his type. I guess in the next poll McCain and Dole will be in there too.