Politics.

"I speak the popular myth of prescience: to know the future absolutely! All of it! What fortunes could be made—and lost—on such absolute knowledge, eh? The rabble believes this. They believe that if a little bit is good, more must be better. How excellent! And if you handed one of them the complete scenario of his life, the unvarying dialogue up to his moment of death—what a hellish gift that’d be. What utter boredom! Every living instant he’d be replaying what he knew absolutely. No deviation. He could anticipate every response, every utterance—over and over and over and over and over and . ."
-Children of Dune.

If a little bit is good, more must be better. One of my favorite lines from the Dune series.
I find most politics to follow this statement. People draw their tribal lines based on their political beliefs. If you're an Objectivist, or a Libertarian, or a Conservative, or a Liberal, it seems all-or-nothing. And I find that kind of thinking useless. Policy is a balancing act between the good of the many and the good of the individual, between what is fair and what is practical, between ideals and reality. Any -ism is destructive when taken to an extreme.
But probably more importantly, ALL -isms are followed by, and implemented by people. People who lie to themselves, who rationalize emotional decisions, who hide their mistakes out of fear and embarassment.

Don't put too much faith in your -ism. You're restricting yourself to only one tool in your toolbox.