At least they're not pretending to have a justification for their absurd, evil lies.
Well, the truly clueless ones—the ones whose sum total of Delusion and Cognitive Dissonance when stacked end to end would dwarf Mt. Everest—aren’t really pretending per se. They truly believe they are not racist and are surprised when their views cause negative reaction.
Now, neither of the types of racists that have been covered here are very pleasant. They fall into the “Can’t Fix Stupid” category. Can’t do much but practice meditation to control your blood pressure when you are around them.
I think when it comes to racism, it is best to deal with the ones that are not so much clueless as simply plagued by garden-variety ignorance. Such folks can, with a bit of effort, be corrected. They are the folks that you can actually make progress with.