A member of the Patriots mailing list once said that you can't reduce freedom to facts and ideas. You also always got to have an enemy. Usually, the more easily accessible the enemy is, the more active the crusade is because this makes the enemy tangible. Bill Clinton united enough voters who hated George Bush to get elected even though the people who voted for him would normally never agree to anything, as reflected by his debacles on taxation and firearms. I'm going to mention this one, but understand that propaganda is not as effective as people make it out to be.
Propaganda is a tool to persuade others to join a crusade.
The Members There are two specific members of the crusades that deserve a little fanfare. First, the leader. The leader usually has an unbelievable ego. A study of leaders of mass movements has that revealed a very typical pattern. The leader was rejected in his field of experience.