Nope. For a simple reason:
Half of the white population are blithering SJW / progressive socialist morons. They are not only devoid of reason but work actively to destroy their own civilisation.
No other race suffers from this. Has it been caused by devolution? By the “enlightenment” (which is a great brand name)? Unknown and irrelevant.
The SJW morons drag the average down so much that whites cannot be the supreme race.
Could whites be the supreme race would they not produce SJW morons? Maybe. But that’s not the world we live in.
Therefore I am NOT a white supremacist. It would be an illogical position to take. I try to avoid that.
P.S.: For the logically challenged, the given reason does not exclude other reasons, like, other races actually being superior. Once we have discarded the claim though, it becomes unnecessary to look for such reasons, of course.