There are a number of different Klan groups. Klan LLC, mentioned in the quote above, claims to be a re-creation of the original Reconstruction era Klan, which they claim (falsely) was not a hate group. Most other groups are derived to some extent from the “modern” Klan, inspired by the movie Birth of a Nation and founded in 1915 at Stone Mountain Georgia. In the 20s this reached monstrous dimensions, with several million members, and practically controlled several states. It collapsed after a series of scandals and disbanded entirely in 1946 because of tax problems. Since then, almost anyone with a hankering for hate has been able to form a Klan of his own.
Naturally, their specific policies on hate would vary. The Reconstruction era Klan, for example, was the most violent of all, responsible for thousands of murders, but it was not particularly antisemitic or anti-Catholic, a stark contrast to the modern Klan groups.