I had no idea
What a strange little law.
Probably a way to make sure that Dixiecrat votes didn't bleed over into REAL liberal votes for the Presidency, in the 1960's and '70's. (Law was passed in 1967). Still...I had no idea.
Jay Hamilton is one of K. Grease's favorite people. Fair-minded, and extremely handsome, for a liberal. He also has this working paper, on the press. Fascinating.