Caro has been at work on his prize-winning LBJ biography for more than three decades. The website Politico summarized Caro's presentation of the JFK assassination as follows:
Caro presents a portrait of a man on the verge of transition. The day began for Johnson with the belief - the fear - that he might not be on the ticket with J.F.K. in the coming election. That very day, back in Washington, a witness was providing Senate Rules Committee staffers with evidence that he said linked Johnson to Robert G. (Bobby) Baker, the subject of a scandal that had been exploding in the capital, and Life magazine was mapping out an investigation into the sources of Johnson's wealth.
'The Vice-President's trip to Texas wasn't going well: he had failed to heal the bitter rift between two major Texas Democrats, Governor John B. Connally and Senator Ralph Yarborough; the previous day, in San Antonio, Yarborough had refused even to ride in the same car with Johnson. "Given what the President was seeing for himself in Texas - that Johnson was no longer a viable mediator between factions of his party in his home state - and what was happening at that very minute in the Old Senate Office Building, the President's assurances that he would be on the ticket might start to have a hollow ring,' Caro writes.
Johnson himself, Caro writes, believed that his political career was 'finished.' Caro then details the moments after the shots were fired - Johnson being flung to the floor of his car by a Secret Service agent who lay on top of him for protection, the tense moments at the Dallas hospital as Johnson awaited news of Kennedy's condition, and the mad rush to get Johnson aboard Air Force One amid fears that the assassination might be part of a conspiracy - during which an immediate change took place in Johnson.
Jack Valenti said that, 'even in that instant, there was a new demeanor' in the new President. 'Whatever emotions or passions he had in him, he had put them under a strict discipline so that he was very quiet and seemingly very much in command of himself." There had been, in Valenti's words, 'a transformation.'