Did he have party loyalties? Sure. Did they sometimes conflict with his personal views? Sure. I'll admit that there were some disappointments.
However, his ultimate ability to break with powerful past loyalties that conflicted with his personal views and to speak publicly about this schism makes him a hero in my opinion.
Though he was a staunch republican at the time, there was a brief moment in my life, when members of both political parties hoped he might run for president under their banner. I don't think that can be said of any other modern figure.