It has its roots in old anti-semitic conspiracy theories, particularly beliefs about blood libel (that Jews would kill Christian children in diabolical rituals) and "Cultural Marxism" (a Nazi-born conspiracy theory that academia is filled with ranks of Jews conspiring to indoctrinate people into Marxist/Communist ideology, which feeds into general conspiracy theories about "the elites" plotting to change/take over the world in some nefarious way.)

Basically the modern version just has the serial numbers filed off and doesn't reference Jewish people directly, just "the elites" (note finance, entertainment and academia have long been considered "Jewish" domains for various reasons.) But if you did deeply enough, it's always there.