During the summers of 1965 and 1966, when I was a student in high school, I worked for several months as a messenger in the White House. I brushed up against a good deal of trivia masquerading as history, such as the extraordinarily elaborate preparations for Luci Johnson’s wedding. But I also attended an event that I knew, even then, was genuinely momentous. I understood that partly because this was one of the only presidential speeches during my months in the White House to take place in the East Room and because there was an unusually large crowd of reporters, television technicians, and White House minions. Lyndon Johnson was announcing his decision to send American ground troops into Vietnam.

We now know, of course, that the United States had been sending troops into combat in Vietnam for many months already at that point. In a sense Johnson was simply acknowledging reality. But he was also signaling a major American escalation of the ground war, and the speech made me think—for the first time—that Vietnam might soon have a direct effect on my own life and on the lives of my contemporaries. Johnson, who usually spoke woodenly and even somewhat distractedly in formal settings, was making a special effort to appear forceful and presidential. But the speech was grim and curiously plaintive, peppered with mawkish readings of letters from soldiers and filled with references to the incomprehension with which he knew much of the public viewed this war. It was the summer of 1965, eight months after his remarkable landslide victory and at the zenith of the Great Society. But at that moment Lyndon Johnson looked, to me at least, like a defeated man.