NAIROBI, KENYA — During an emotion-packed visit to his father's homeland in 2006, Sen. Barack Obama took time from family reunions and official visits to chastise Kenya's government for failing to stem corruption and tribalism, irking his hosts in the process.
It wasn't the first time an Obama had taken Kenya's elite to task. Forty years earlier, a rising star named Barack Obama -- tall, elegant and impeccably dressed -- attacked the nation's post-independence government, accusing leaders of betraying their ideals and replicating the nepotism of departing colonialists.
"It must be something in our family," observed a smiling Said Obama, younger brother of Obama Sr.
Although the lives of father and son scarcely intersected beyond a few letters and a 1971 visit in Hawaii when the younger Obama was 10, friends and family see similarities in the men's charisma and eloquence, even if their lives took dramatically different turns.
Both achieved success at a young age. Both advocated change. And both displayed a self-confidence that friends described as bordering on cocky.
"The father was full of life, ebullient and arrogant, but not unpleasantly so," recalled Philip Ochieng, a former drinking buddy of Obama Sr. and veteran Kenyan journalist.
"But in many ways, the son is quite the opposite. He has self-control. The ambition is controlled. And he has a more sober mind."
The elder Obama was one of Kenya's most promising sons, rising from the goat pastures of a western village to the study halls of Harvard, eventually taking a coveted spot among the nation's post-colonial government leaders.
He often introduced himself as "Dr. Obama," though there is no record of him completing a doctorate. He was a heavy drinker, ordering straight scotch by the "double double," or four shots at a time. Beer, he said, was a "child's drink."
He is best remembered for his booming baritone, which intimidated opponents and charmed women, friends said.
One of those was Ann Dunham, who met Obama Sr. while both were studying at the University of Hawaii in 1959. They separated a few years later when Obama got a scholarship to Harvard, leaving Dunham to raise their son, Barack Jr.
Sen. Obama has spoken often of the effect of his father's abandonment. At first, he said, it pushed him to try to live up to the expectations of an absent, almost-mythical figure. Later, as he learned the details of his father's troubled life, he said that it propelled him to try to make up for Obama Sr.'s shortcomings.
"He was a brilliant guy," Obama told biographer David Mendell, "but in so many ways his life was a mess."
Despite his ambition and talent, the elder Obama's career disintegrated amid external forces and personal weaknesses, including the alcohol problem, which led to a string of car accidents. A crash in 1982 took his life.
Friends and family say his career imploded in part because of his brash personality and an idealistic belief, nurtured in America, that the best ideas and smartest people would always rise to the top. Confronted with the reality of corruption and cronyism in Kenya, Obama sank into disillusionment and despair.
"To that extent, he was naive," said his friend Peter Aringo, a longtime member of parliament from Obama's home village. "He thought he could fight the system from the outside. He thought he could bring it down."
Instead, it brought him down.
From a young age, Obama was the village's pride. His father was a respected chieftain, known as one of the first in his Lake Victoria village to befriend British colonialists, learn English and adopt their style of dress. (As a boy, upon hearing stories that his grandfather was a village chief, Sen. Obama envisioned his father as an African prince, he wrote in his 1995 autobiography, "Dreams From My Father.")
After excelling in school, Obama Sr. moved to Nairobi, the capital, where he caught the eye of Tom Mboya, one of Kenya's founding fathers. Mboya selected Obama and about 80 other students to send on scholarships to U.S. universities in a 1959 "airlift" in anticipation of Kenya's independence in 1963. The students included Wangari Maathai, who became the first African woman to receive the Nobel Peace Prize.
"There was so much excitement during that time," recalled Mboya's widow, Pamela, one of those on the trip. "We were going to the U.S. to be educated so we could come back and take over, and that's exactly what we did."
In Hawaii, Obama wooed and married Dunham, the progressive only child of Kansas parents. The interracial relationship raised alarm on both sides of the family; their son was born Aug. 4, 1961.
Obama Sr. left Dunham and Barack Jr. after winning a graduate scholarship to Harvard; he enrolled in September 1962, records show. Family members say Obama Sr. could not afford to take his new family but felt he could not pass up the chance to attend one of America's best universities.