You realize this quote is about communism and J Edgar Hoover's almost insane obsession with it than it is about conspiracies in general? In fact his fears of communism was as deluded as a lot of conspiracy theorists are and led to the government to abuse its power. He used his fear of communism to do a lot of the things conspiracy minded people fear which is unlawful surveillence of "enemies of the state", dehumanization and harrassment of "Anti-establishment" leaders like MLK who he personally wrote a letter to tell him to kill himself and constantly accused of being communist, and a large number of other abuses.
How dishonest of you to leave off the first sentence of the quote.
How am I being dishonest? While it addressed Communism, Hoover himself used and created conspiracies against black people and others who went against the system. The quote isn't meant for one thing and one thing only, especially since he tactics span 50 years.