Mr. Schomp, who describes himself as an ambitious and spoiled young man, joined the Birch Society in 1964 and this is a heavily self-conscious ""expose."" He became a chapter leader and coordinator in St. Petersburg, Florida where he gave presentations for prospect-joiners. Robert Welch, whom he claims looks like a fatherly Mr. McGoo (in fact most Birch-ers seem faintly comic in his retrospect) works tirelessly at 70 and sees ""insiders under every bed."" As for the others, however anti-Semitic or closed-minded, they seem to be faddish kookniks and are perhaps too indulgently viewed here. One is given every reason to believe that Schomp joined the Society for muddled reasons of ego-gratification and his clucking over the idiocy of the other Birchers is tinged with his own brand of idiocy. Worse yet, while claiming to have written the book as a ""cleansing agent,"" it seems more like a buoyant leap into opportunism.