For months, I searched for the larger principles or sense of purpose that animates McConnell. I travelled twice to Kentucky, observed him at a Trump rally in Lexington, and watched him preside over the impeachment trial in Washington. I interviewed dozens of people, some of whom love him and some of whom despise him. I read his autobiography, his speeches, and what others have written about him. Finally, someone who knows him very well told me, “Give up. You can look and look for something more in him, but it isn’t there. I wish I could tell you that there is some secret thing that he really believes in, but he doesn’t.”

The notion that McConnell started out as an idealist is a staple of most versions of his life story, including his own autobiography, “The Long Game,” published in 2016. He describes his awe, as a young congressional intern, at seeing crowds gather on the Washington Mall for Martin Luther King’s “I Have a Dream” speech, in 1963. McConnell, who was on summer break from the University of Louisville, writes that he recognized he “was witnessing a pivotal moment in history.”

McConnell was born in Alabama in 1942, and grew up in the segregated Deep South. He spent much of his childhood in Georgia before moving with his family to Louisville, Kentucky, just before his high-school years. His mother, the daughter of Alabama subsistence farmers, was a secretary in Birmingham when she met McConnell’s father, a mid-level corporate manager who had grown up in a more prosperous family but had dropped out of college. McConnell, in his autobiography, describes his mother’s wedding dowry as little more than “an apple corer and a can opener.” But his parents, he writes, gave him a comfortable middle-class childhood and “instilled me with a deep-seated belief in equal and civil rights, which, given their own upbringing in the Deep South, was quite extraordinary.” He quotes a moving letter from his father celebrating the passage of the 1964 Civil Rights Act, and writes that he, too, supported the legislation. That year, McConnell even voted for Lyndon Johnson for President.

McConnell’s book does not mention that his father, who worked in the human-resources department at DuPont, was deposed by lawyers for the N.A.A.C.P. Legal Defense and Educational Fund in a historic racial-discrimination case. Kerry Scanlon, one of the lawyers, told me, “The leadership at that plant seemed to define racism. There was a plantation system in which the black employees did the hardest jobs, like working in front of these open fires where they got burned—and they got the worst pay. There was a systemic pattern of racism.” After years of litigation, the company settled the case, for fourteen million dollars.

McConnell writes that the formative experience of his early life was contracting polio at the age of two, ten years before Jonas Salk developed his vaccine. McConnell’s father was away, having joined the military after the start of the Second World War, and so for the next two years his mother, largely alone, confined him to bed except for a painful daily regimen of exercises. His first memory is of his mother’s purchase of a pair of saddle shoes that allowed him to look like other kids once the doctors finally allowed him to walk. He emerged unimpaired, other than having a weak left leg. He credits the experience, and his mother’s determination, with giving him the focus and drive that have propelled him throughout his career. Beating polio, he writes, was the first in a lifetime pursuit of hard-fought “wins.” In recent weeks, as McConnell has contended with the coronavirus challenge, he has said that it brings back “this eerie feeling” of “fear that every mother had” during a polio epidemic.