‘Becoming FDR: The Personal Crisis That Made a President’
By Jonathan Darman
Random House, 448 pages

‘Hoover vs. Roosevelt: Two Presidents’ Battle over Feeding Europe and Going to War’
By Hal Elliott Wert
Stackpole Books, 536 pages

‘Unlikely Heroes: Franklin Roosevelt, His Four Lieutenants, and the World They Made’
By Derek Leebaert
St. Martin’s Press, 496 pages

FDR’s story is tempting to novelize, as Jonathan Darman does, in portentous prose: “Destiny was indeed a mysterious thing; Franklin Roosevelt had learned that long ago. As a young man, cosseted in his own palace of privilege, he had believed himself destined for glory. He had thought that if he followed a straightforward path from success to success, greatness would surely come. Then one awful day, illness had surprised him, mocked his certainty, and tossed his expectations aside.”

This would be a good setup for a children’s biography: “But the stroke of fate that had turned his legs lifeless had also made him the man who could inspire and lead his country that night” in 1936, at Philadelphia. “Polio had remade his life, created a more gifted, intuitive, compassionate politician, made him a better man.”

Was it FDR’s response to polio that made him great? How could it be denied as a factor, but was catching the disease dispositive? Was the anti-New Dealer, Herbert Hoover, the tremendous organizer of food distribution in 38 countries after World War II — not to mention his similar great humanitarian achievements in World War I — any less compassionate than FDR?

Hoover, Hal Elliott Wert contends, prompted Roosevelt to do much more in terms of aid to the starving than FDR had projected in his policy prescriptions. The positive Hoover story has been obscured by the contentious political debates between the two presidents, but has now been fully illustrated in Mr. Wert’s acute treatment of the intersections between personalities and politics.

In “Unlikely Heroes,” Derek Leebaert acknowledges the importance of FDR’s struggle with polio, effectively expressed in Kipling’s poem “If,” which presents, as the biographer observes, “life as a continuous test” that has to be won again and again. Yet “Unlikely Heroes” concentrates not so much on FDR himself but on his choice of “strange outsiders” — four lieutenants each damaged but undaunted in their own inimitable ways.

“Unlikely Heroes” portrays a tough-minded president who shrewdly read human personalities who on their own — given their peculiarities — could never have ascended to the precincts of presidential power.

Roosevelt relied on all four to crack through the concentrations of authority in government bureaucracy. In Mr. Leebaert’s telling, FDR “could sense their despair even as they built the great institutions being raised against the Depression, implementing most of the projects and reforms known as the New Deal that remade the country, and proved themselves vital to victory in World War II.”

“The best way to come to terms with Franklin Roosevelt,” Mr. Leebaert argues, “as well as to penetrate the maze of his presidency,” is to take a “synoptic” view that arises from examining the lives of lieutenants, who, on their own, might well have come to grief.

Hopkins, who seemed to be dying during much of Roosevelt’s presidency, became the wounded warrior who “refused to leave the field. This became a source of power, and it drew him closer to FDR.”

Harold Ickes, a failed Republican kingmaker who called himself a loser and a manic-depressive, got turned around by FDR, who made him the “watchful monarch” of what seemed like everything from building public works to “Negro Affairs.”

Frances Perkins hailed back to a time when Roosevelt vaulted over chairs like some “Greek god king of an athlete,” but she hated the limelight and had to be coaxed along to do her ground-breaking work on Social Security and immigration and on wide-ranging labor issues while dealing with the enormous expense of institutionalizing her manic-depressive husband.

To many, Henry Wallace, then in his prime at 45, seemed nonetheless a freak as well as a world class agronomist with a vision of a post-war world that inspired FDR to make him his vice-president in 1940.

What FDR’s leadership of these unlikely heroes shows is that empathy and grave illness are not enough to explain the political genius of a man who triumphed not because of his disabilities but in spite of them.

Mr. Rollyson’s work in progress is “Making the American Presidency: How Biographers Shape History.”