Jimmy Carter is usually regarded as a failed president and America's greatest former president. In "His Very Best," the first full-length biography of the 39th president, journalist Jonathan Alter (author of "The Defining Moment: FDR's Hundred Days," and "The Center Holds: Obama and His Enemies") maintains that Carter was "not a great leader but a significant one."

Alter's scrupulously researched and judicious book depicts Carter as a man with a first-class intelligence and a second-class temperament; better at sermonizing than mobilizing; a technician rather than a grand strategist, unable to fit his beliefs into a compelling ideological package or combine policymaking with politics; prescient on climate change and human rights; weak on issues that mattered most to voters, the economy and Iran hostage crisis.

Drawing on dozens of interviews, Alter provides a fascinating account of Carter's formative years, where, by the standards of Plains, Ga., Jimmy was a racial moderate: alone in advocating that Blacks be permitted to worship in his church; silent on school desegregation; cozying up (during his race for governor) to the founder of the state's White Citizens Council and George Wallace; declaring in his inaugural address "the time for racial discrimination is over," and appointing African Americans to government offices.

A virtual unknown, running against a weak field, Carter won the Democratic nomination for president in 1976, Alter reminds us, by running as an outsider in a post-Watergate climate of distrust in and disillusionment with government. As president, he never mastered the horse trader's art of working Congress. Nor, Alter indicates, did he appreciate that the presidency "is not just a fishbowl but a theater," a stage from which to project an image.

Alter also provides a candid and often compelling assessment of Carter's policy successes and failures. He tackled the unpopular issue of energy conservation, imposing fuel economy standards and incentivizing renewables; launching initiatives on clean air and water, natural gas, and a Superfund to remove toxic waste; designating vast areas in Alaska and elsewhere as public lands, monuments and parks. Carter failed, however, to follow up on his "malaise" speech. He didn't get Congress to adopt tax or welfare reform, consumer protection or health care.

In foreign policy, Alter acknowledges that the president was slow and unimaginative in responding to developments in Iran. And he suggests that the Camp David Accords may inadvertently have freed Israel to attack Palestinians in Lebanon and build more settlements on the West Bank. That said, critics may find Alter's overall assessment too generous. The world is safer, he asserts, because Carter normalized relations with China. His Panama Canal Treaty "almost certainly prevented a long and bloody guerrilla war again the United States." And the president made human rights "a permanent feature of global political discourse."

After Carter's defeat for re-election, Vice President Walter Mondale proposed a toast: "We told the truth. We obeyed the law. We kept the peace." At the time, Alter writes, "these might have seemed modest accomplishments." But, he implies, not now.

Glenn C. Altschuler is the Thomas and Dorothy Litwin Professor of American Studies at Cornell University.

His Very Best
By: Jonathan Alter.
Publisher: Simon & Schuster, 800 pages, $37.50.