Complex sentence: The Klu Klux Klan, which was growing into a powerful force through the 1920s, spread the bogus oath far and wide as part of their campaign against Catholics, and in the 1928 Presidential election a million copies were printed to hurt Catholic Democratic candidate Al Smith.
Split into simpler sentences: The Klu Klux Klan, which was growing into a powerful force through the 1920s, spread the bogus oath far and wide as part of their campaign against Catholics. In the 1928 Presidential election a million copies were printed to hurt Catholic Democratic candidate Al Smith.