Jeb is exactly the kind of person who makes a great governor. A legislator needs to be partisan and push for advantage in order to achieve the agenda. He represents the people who elected him.
But a governor needs to be the leader of all the people and do what is best for his state. That doesn't mean that he can't fight for the things he believes in. He should. But it means that you're also governor for the people who didn't vote for you, and you shouldn't ignore their legitimate needs, too.
Who knows, they may end up being a former Democrat like you.