One of the top people in the JBS in the early years (on its board of directors or the equivalent) was Revilo P. Oliver, professor of Classics at the University of Illinois, who was a raving anti-Semite and also racist about blacks. He was kicked out after his comment after John F. Kennedy was assassinated (to the effect that the Communists got rid of Kennedy after he had finished serving their purposes). I don’t know if Robert Welch was aware of Oliver’s anti-Semitic pronouncements.
Revilo Oliver (Revilo is Oliver spelled backwards) made his comment about JFK in his article "Marxmanship in Dallas" published in American Opinion magazine, the JBS house organ, in February, 1964. But Oliver left the JBS in the summer of 1966--I heard that it was due to some Judeophobic remarks he had made at a rally. However, he claims in an article available on a website devoted to him that he resigned from the JBS because he discovered that it was controlled by a "committee of Jews."
Actually, VR, Oliver was not “kicked out”. He resigned. Robert Welch traveled to Oliver’s home in Urbana IL and asked him to reconsider. I have copies of Oliver’s correspondence with JBS National Council members as well as Robert Welch’s memo to all National Council members concerning the Oliver controversy.
After Oliver left the JBS he started writing articles for the neo-nazi magazine, Liberty Bell, published by George P. Dietz. Dietz was also a former JBS member.