@Frank Apisa,
People have known been to change their opinion. Think back a few years to a time when former NYC Mayor Rudy Giuliani was considering a presidential run. For a time he was at the top of the list for candidates people would vote for. By the time the primaries got going, he was not any longer the front runner. Things got so bad that he took ill on one of his campaign tours (I believe he was out in Missouri at the time).
Regarding the poll, it's Jersey based which gives the bias of residents of the Garden State. These people know him a bit better than the folks in downtown Bemidji so they have a better handle on how non-presidential he is. Then again, they did reelect him as Governor.