"In many ways Johnson was inadequate to the demands of the modern presidency, especially as a public educator," wrote political scientists Sidney Milkis and Michael Nelson in The American Presidency: Origins & Development 1776-1998. "Unlike other twentieth-century presidents who wanted to remake the nation, LBJ neglected, even scorned, the 'bully pulpit.' Yet Johnson profoundly influenced the modern presidency in other ways. He more than maintained the power and independence of the executive office. Regrettably, his failings also brought into serious question—for the first time since the 1930s—the widespread assumption that the national interest is served whenever the president dominates the affairs of state. The disillusionment with executive power that commenced late in Johnson's tenure actually began to unravel some of the conditions that had given rise to the modern presidency."
As the Vietnam War escalated, with soaring costs in lives and resources, and as the nation's domestic divisions intensified over Johnson's ambitious social programs, the president's popularity sank. He declined to run for re-election in 1968 and left office a very unpopular man.
But in the beginning, he seemed to be a force of nature. In an interview with three network television journalists March 15, 1964, Johnson assessed his first 100 days. "The first priority," he said, "was to try to display to the world that we could have continuity and transition, that the program of President Kennedy would be carried on, that there was no need for them to be disturbed and fearful that our constitutional system had been endangered. To demonstrate to the people of this country that although their leader had fallen, and we had a new president, that we must have unity and we must close ranks, and we must work together for the good of all America and the world."
Johnson accomplished those initial goals admirably well.