The Knights of Columbus is a Catholic men's fraternal benefit society that was formed to render financial aid to members and their families. Mutual aid and assistance are offered to sick, disabled and needy members and their families. Social and intellectual fellowship is promoted among members and their families through educational, charitable, religious, social welfare, war relief and public relief works.
As for understanding "McCarthyism"...what is there to understand? Spanish Inquisition, Salem Witch Hunts...history replayed.