The utter inability to comprehend the questions of morality or ethics raised by his actions

When they [Johnson’s Lawyers] gave clients advice, the clients usually followed it. Lyndon did not follow it. During the next few days in that September 1948 – those days of crisis – he was to display vividly many of the most striking qualities of his nature. One was the fierceness and determination with which he grabbed for political advantage, grabbed it and, one he had it in his grasp, held onto it. … Another was the utter inability to comprehend the questions of morality or ethics raised by his actions, an utter inability to feel that there was even a possibility that he had violated accepted standards of conduct and might be punished for that violation. But, during this conference and during the following days, Lyndon Johnson was also to display many of the qualities that made him a leader of men. [These were responsibility, decisiveness and force of personality] 

R. Caro, The years of Lyndon Johnson, Volume 2: means of ascent (1990), 357