Radicals on all sides of the political spectrum have far more in common with each other than with normal people.  It isn't their philosophy that makes them similar but their methods.  The one thing that they have in common is a radical intelorance for opinions other than their own.

So, in my mind, whether they are promoting communism (Mao, Stalin), racism (Hitler) or religion (Isis) they are all evil and must be opposed by all decent people.