Well at least you recognize that a fear can be irrational. and even if it does feel "real" to the person, that doesn't make it rational or logical in the real world no matter which side of the political spectrum one is on. The universality of irrational fears does nothing to make them realistic. 

Your example of the anti-Harper fear mongering is an excellent one, and it proves that these kinds of fears are unfounded. The difference is that it's one thing to fear an individual, it's a whole other level of irrationality to assume that all Muslims are to be feared and that they all have the destruction of the west at heart.