The McCain family, as described in Faith of My Fathers, was traditional. The candidate's father, John McCain Jr., who died in 1981, was a four-star admiral in the navy; his mother, Roberta, stayed at home to raise the children, though she was, as she once told her son, devoted to her husband first and foremost. The emotional life of the household was one of composed restraint—as much a reflection of the time period as it was a conscious part of the McCain family ethos. "By your father's calling, you are born into an exclusive, noble tradition," McCain writes of his naval heritage. "Your father's life is marked by brave and uncomplaining sacrifice. You are asked only to bear the inconveniences caused by his absence with a little of the same stoic acceptance. When your father is away, the tradition remains, and embellishes a paternal image that is powerfully attractive to a small boy, even long after the boy becomes a man." (It is worth noting that, despite McCain's solemn writing style here, he frequently describes a more carefree side of himself—one who threw toga parties and dated Marie, "the Flame of Florida," an exotic dancer he met in a bar.)

Obama explores his family history in his eloquent book Dreams from My Father. He is the child of an interracial marriage—a defiant union even for the progressive '60s—between his white, Kansas-born mother, Stanley Ann Dunham, and his Kenyan-immigrant father, Barack Obama Sr. His now famously single mother raised her son without a husband from the time Obama was 2—when his father left to attend graduate school at Harvard; Obama Sr. later moved back to Kenya, where he remarried and fathered six more children.

Dunham was fiercely independent: She moved to Indonesia, the homeland of her second husband (whom she would also divorce), received her Ph.D. in anthropology, and went on to bring crucial economic attention—among other things, by championing microcredit for the poor—to neglected communities throughout the world. She also made bold parenting decisions, like sending her 10-year-old son to live with her parents in Hawaii, where she believed he would get a better education. Obama's unorthodox upbringing—the disparate cultures of his parents, the largely unknown father and siblings in Africa, the identity questions provoked by being both white and black—left him with a conflicted and shifting sense of family.

"No one here could tell me what my blood ties demanded or how those demands could be reconciled with some larger idea of human association," Obama writes of a pilgrimage he made to Africa to better understand his by-then deceased father. "It was as if we—[my half siblings] and I—were all making it up as we went along. As if the map that might have once measured the direction and force of our love, the code that would unlock our blessings, had been lost long ago, buried with the ancestors beneath a silent earth."

Despite the fact that both McCain and Obama have spent a good deal of their lives, and their memoirs, hunting the ghosts of their fathers, they are guided by different instincts. McCain was born into his destiny, inasmuch as one can be. "My grandfather was a naval aviator, my father a submariner," he explains. "They were my first heroes, and earning their respect has been the most lasting ambition of my life. They have been dead many years now, yet I still aspire to live my life according to the terms of their approval."

Next Page: "These distant fathers so inhabited the minds of their sons, there is little room left for the mothers, it seems, although both men write with adoration in the passages they do devote to them."