Adversity remade into triumph. It is, of course, the oldest plot in the ''Inspirational Film" book, that fat tome on the shelf beside ''How to Tap Sap." The familiar arc goes like this: Give a person a crippling illness. Throw him into a spiral of self-pity. Evolve him into a noble hero. Put big lumps in viewers' throats.
Too often in entertainment, suffering is reduced to an easy lesson in character building. It gets cut down into dime-store uplift. But when the pain-to-gain genre is done right, and HBO's FDR drama ''Warm Springs" is right enough, it can isolate and honor the redemptive potential of hard times. It can almost make you feel that there's some virtue in grief, despite the reality once named by poet Randall Jarrell, who wrote, ''Pain comes from the darkness / And we call it wisdom. It is pain."
''Warm Springs," which premieres tomorrow at 8 p.m., argues that suffering was the critical element in what ultimately made President Franklin Delano Roosevelt (Kenneth Branagh) a man of greatness. The movie's little-known chapter of history starts with Roosevelt's journey into a hard-drinking depression after he contracts polio at age 39, in the middle of a political career that had already included an unsuccessful run for vice president. And it ends with his return to public life, renewed and spiritually enlarged, a tree with stronger roots after withstanding the gales of winter. He grows from a glad-handing aristocrat into a deeper man of the people, destined to serve four terms as the leader of the country.
In between those two ends, ''Warm Springs" shows Roosevelt shedding his despair and finding hope and willpower at a rundown spa in rural Warm Springs, Ga. In constant pain, he became physically buoyed by the mineral-rich waters there, which were said to benefit those with polio. But he was also emotionally awakened by the culture of the backwoods South -- by the poverty, by an intimacy with black people still afraid for their lives, by a close-up view of the less fortunate. For the first time in his life, he was grouped with social outsiders, since people with polio were often feared back then. Warm Springs became the one place where he didn't see pity or disgust in people's eyes, as they watched him struggle with his braces and misshapen legs.
His stays at the spa also provided Roosevelt with an escape from his family, notably his put-upon wife, Eleanor (Cynthia Nixon), whom he affectionately called ''Babs." Their marriage was already strained, after she'd discovered his affair with her secretary, Lucy Page Mercer, and though she was still with him and raising their five children when he became ill, she was not with him in spirit. And Roosevelt's severe mother, Sara, further complicated the home front. Jane Alexander, who delivered an unforgettable performance as Eleanor in 1976's ''Eleanor and Franklin," puts in a small but potent appearance as Sara, who threatened to withhold money if the couple broke up. ''Divorce Eleanor and there is no trust fund," she announces to her son.
At the spa, which Roosevelt eventually buys and turns into a rehab facility, he serves as the patriarch of a far less fraught family. This aspect of ''Warm Springs" can be too quaint for its own good, as the bonds among the polio sufferers and health-care workers at the dilapidated facility takes on a decidedly ''Waltons"-like tone. Kathy Bates is the stoic physical therapist with a heart of gold, and Tim Blake Nelson plays the selfless director of the spa. As they push Roosevelt spiritually, in the same way political adviser Louis Howe (David Paymer) pushed him professionally, the script sometimes becomes too sentimental. While Roosevelt may have opened up among these people, he did remain something of a hail-fellow-well-met all along.
Fortunately, Branagh manages to stay true to that aspect of FDR, even when the script doesn't. His performance is the best thing about ''Warm Springs," as he evokes both the figure with the cigarette holder we've seen in news footage and then a less well-known man prone to temper tantrums and cynicism. He believably extends FDR's character into weakness without seeming to clash with our perception of the politician with the virile smile. Branagh is helped by director Joseph Sargent, who keeps the movie's tight focus on his performance and not on the unfolding history.
Nixon fares well, although not as well as Branagh. She brings an effectively tentative voice to Eleanor, as well as a manner that manages to be both mousy and steely. She admirably holds her own in her scenes with Branagh. But she seems not to have mastered the prosthetic teeth, looking a bit like someone trying to store a mint in her upper lip. It takes some time to get used to watching her talk. And her character development from wounded woman to empowered political ally doesn't get quite enough screen time to work. It seems like an unearned transformation. But then ''Warm Springs" is truly meant to be the story of FDR -- not the public president who hid his paralysis from Americans, but the private man who dealt with a profound disability.