Here's a blog I found at mentalfloss.com. Apparently, in the 1940s, this writer went undercover to Klan meetings and found out a whole bunch of their secrets and that recruitment was in full effect. But when he took his info to the cops, they were too scared to do anything so the guy took the info to the people behind the Superman radio show. They dissed the KKK and revealed a whole bunch of shady stuff about it and enrollment eventually dwindled:
Struggling to make use of his findings, Kennedy approached the writers of the Superman radio serial. It was perfect timing. With the war over and the Nazis no longer a threat, the producers were looking for a new villain for Superman to fight. The KKK was a great fit for the role. In a 16-episode series titled “Clan of the Fiery Cross,” the writers pitted the Man of Steel against the men in white hoods. As the storyline progressed, the shows exposed many of the KKK’s most guarded secrets. By revealing everything from code words to rituals, the program completely stripped the Klan of its mystique. Within two weeks of the broadcast, KKK recruitment was down to zero. And by 1948, people were showing up to Klan rallies just to mock them. More here.
Why didn't the civil rights movement didn't think of that?
BTW, re: above photo, completely gratuitous but totally appreciated.
yea this was featured in the good documentary Look, Up in the Sky: The Amazing Story of Superman. needless to say, superman is badass.