As Carl Cannon reported in these pages last month, White House staffers have taken to calling Clinton aide Sidney Blumenthal "G. K." -- short for " grassy knoll" -- in honor of Blumenthal's predilection for conspiracy theories. But even the most diligent Blumenthal fans may not know how deep- seated that passion is.

THE SCRAPROOK recently checked out of the Arlington, Va., public library (the Library of Congress's copy was inexplicably missing) a bizarre little paperback called Government by Gunplay: Assassination Conspiracy Theories from Dallas to Today. Copyright 1976, and edited by Sid Blumenthal.

"Conspiracy is an ugly word," screams the cover blurb, "but what has been happening in America for 15 years is ugly. . . . This shocking book puts all the conspiracy concepts together. Here are probing examinations of the crimes themselves, conclusive critiques of governmental whitewashings . . . and the danger they pose for our national integrity and our individual liberties."

The articles that Blumenthal assembled for the book touch all the conspiracists' hot buttons. "What role did the FBI play in the killing of Kennedy?" asks the chapter on Lee Harvey Oswald. An analysis of the Zapruder film proves, perhaps for the first time, that there were four (4) assassins in Dealey Plaza (and you thought there were only three!). An article on the shooting of George Wallace tries to link Wallace's assailant, Arthur Bremer, with the Nixon White House and presents the shooting as a kind of pre-emptive coup: "Bullets instead of ballots had once again dictated who would be president."

As an author, Blumenthal also penned his own contributions to Government by Gunplay, and they are slightly less wacko -- slightly. In one chapter, he illuminates "How the FBI Tried to Destroy the Black Panthers" (by bumping them off, mostly). "The elimination of the Panthers as a political force," Sid writes, "was a preceding step to Watergate, flowing sequentially into it."

This is a pure expression of the paranoid style, and you could dismiss Government by Gunplay as the work of an overexuberant young man -- except by all accounts Blumenthal still thinks this way, and is doing his thinking from a taxpayer-funded perch in the White House. Blumenthal writes in the book: "The guardians of the established order see themselves as the only fit rulers." Well put.