From SNL:
On a more serious note, here's a piece at the Southern Poverty Law Center on the groups that Gibson and his dad are part associated with: The New Crusaders - The radical traditionalist Catholics, who reject the teachings of the modern papacy, may form America's largest group of anti-Semites.
My previous post on Gibson's background is here.
[h/t to Alice J for the video and Adam Holland for the SPLC link]