If what you say is correct about the report being virtually identical to a Southern Poverty Law Center document, then Michael Savage’s hunch may be correct that the author is one Mark Potok, a leftwing lawyer with that outfit.
I’m saying that the tone is similar to SPLC materials. and that there is at least one demonstrable instance of a paragraph lifted directly from the previously cited web page and being used in the report without attribution or quotation marks.