Again, whether a congressman is drunk or a KKK member doesn’t matter one way or the other. The idea stands (or falls) on its own merit, not the character of the person who proposed it.
So what’s wrong with flying the swastika from your rooftop? Is there anything wrong with the “idea” or “merit” of flying a swastika if it doesn’t stand or fall over the characters of those who proposed it as the Nazi flag? (And it has a history preceding the Nazi’s.)