Historical DA Case File 004: The Kalergi Plan

Case File 004 of Historical Detective Agency research into popular historical myths.
A popular allegation is that one of the founders of the European Union, Count Kalergi, was Jewish and promoted immigration in order to replace Europeans for a "Jewish Takeover".
The "Kalergi Plan" is a common allegation among many anti-Semites, but do the facts support any of the allegations?