Goodwin’s special strength as a historian has always been her ability to present subtle, complex studies of her subjects’ personalities and to show how they interact with their times. Decades ago, as a graduate student in political science, she took an interest in the application of psychoanalytic theory to biography, as pioneered by Erik Erikson, among others. Although only her Johnson book trafficked explicitly in psychoanalytic methods and concepts, this education quietly informed her later work, which benefited from her focus on her protagonists’ upbringing, personality and human relationships. In “Leadership,” too, she renders her characters with a depth and intricacy that not all academic historians seek to attain. Her Lincoln, for example, suffered from debilitating depression, as we know; but she also reminds us that he developed a mordant wit that reflected a deep stoicism — and goes far in explaining why the weight of his melancholy didn’t derail his career.

Goodwin sees complexity, too, in the beguiling Franklin Roosevelt, who, for all his cheerfulness, possessed a fierce, even ruthless ambition. Her account of his drive to conquer his polio so that he could traverse the Madison Square Garden stage at the 1924 Democratic convention exemplifies her talent at bringing personality to life not through didactic exposition but through well-wrought narrative. She describes Roosevelt preparing for his convention walk by measuring off the distance in his library in the family’s East 65th Street house, then digging into his teenage son James’s arm with a grip “like pincers,” as he practiced hoisting his inert, braced legs across the room. At the convention itself, Goodwin recounts the tension in the arena as Roosevelt triumphantly hauled himself across the stage, on just his crutches, to seize “the lectern edges with his powerful, viselike grip” and flash his beaming smile to the cheering throng.

In contrast, when Goodwin gets to her section on the four presidents’ emergency leadership, which should be the book’s pièce de résistance, she succumbs to the leadership genre’s vocabulary of self-help bromides and bullet-point banalities. Otherwise bracing accounts of Lincoln guiding the nation through the Civil War and Johnson shepherding the 1964 civil rights bill into law are punctuated by boldfaced, italicized subheads dispensing wisdom like “Anticipate contending viewpoints,” “Shield colleagues from blame,” “Rally support around a strategic target” and “Give stakeholders a chance to shape measures from the start.” These conference-room poster slogans protrude in the text like hurdles obstructing a runner’s path. They interrupt the flow of the stories while unfurling what are fairly self-evident, common-sensical streamers of advice.

Still, it would be unfair to deny the value in thinking collectively about these four presidents, especially in these dark times. Because so much recent commentary on our presidents has been negative — remembering Lyndon Johnson only for Vietnam, Franklin Roosevelt for barring the gates to Jews fleeing Hitler, Theodore Roosevelt for his imperialist swagger and even Abraham Lincoln for the limits of his racial egalitarianism — we can benefit from reminders that even flawed mortals can, in times of national emergency, achieve great things. We can only hope that a few of Goodwin’s many readers will find in her subjects’ examples a margin of inspiration and a resolve to steer the country to a better place.