Six hundred pages stand here and nearly every one is impossible not to read from first line to last. This political biography by the buoyant pair of Republican-leaning journalists, nationally syndicated in a tandem, truth-telling pair during the past few years, tells us about Lyndon Johnson's political life, from his origins as a call-boy on the New Deal stage to his current experiments in consensus and napalm farming. Friends, enemies, confidants and public observers have added to the picture the twins estimate from their own, two-decade Washington residency. The first half is more exciting to read than the second. It concerns L.B.J. as young Congressman, Senator, his rise to Minority Whip, Majority Leader, his methods of conducting Senate business--of which Evans and Novak are highly critical--the famous Johnson ""Treatment,"" used to cajole backers and voters, the Johnson Network of those in his back pocket, his relationship with a series of ""father figures"" from Roosevelt through Carl Vinson, Sam Rayburn, and Richard Russell. But if the stage is narrowed as Johnson moves on to accept the Vice-Presidential nomination, the stakes are raised. His shift from liberal, Populist politics and techniques to a quasi-conservatism becomes clear as the success of his plans to move from the narrow base of Texas politics to the national scene is achieved. We know more about what happens from the first Kennedy campaign onward to the current dilemma over Vietnam, but that does not dispel the fascination generated by Johnson's character and actions. Perhaps, generations hence, they will read the story of Johnson's movement to the crossroads of Vietnam as we read the tragedy of Oedipus making his way to Thebes. The tone of the book changes, as it moves closer to its contemporary end and question mark of what Johnson will do about the War: from clear disdain to distant admiration. Perhaps Evans and Novak felt, as they wrote, some of the weight L.B.J. must think of as God's Heel. This biography gives us, as no book yet has done, the opportunity to know our Leader--this Principal who seeks power as an anti-aircraft missile seeks heat.