On the day that George W. Bush was sworn into his second term as governor of Texas, friend and adviser Dr. Richard Land recalls Bush making an unexpected pronouncement.

"The day he was inaugurated there were several of us who met with him at the governor's mansion," says Land, president of the Southern Baptist Convention's Ethics & Religious Liberty Commission. "And among the things he said to us was, 'I believe that God wants me to be president.'"

How George W. Bush became a born-again Christian -- and the impact that decision has had on his political career -- is the focus of FRONTLINE's report, "The Jesus Factor." Through interviews with Bush family friends, advisers, political analysts, and observers -- as well as excerpts from the president's speeches, interviews, and debates -- this one-hour documentary chronicles George W. Bush's personal religious journey while also examining the growing political influence of the nation's more than 70 million evangelical Christians.

"President Bush has been called the most openly religious president in modern history," says producer Raney Aronson. "The documentary explores what that means for George Bush, both as a person and as president of the United States."

"The Jesus Factor" recounts how George Bush -- struggling with business failures and a drinking problem -- made a life-altering decision in the 1980s after spending a weekend with longtime family friend Billy Graham: "It was the beginning of a new walk where I would recommit my heart to Jesus Christ," Bush later wrote. The change that decision produced in his life, friends say, was both remarkable and genuine.

"It wasn't just a flash in the pan," says Mark Leaverton, co-founder of the Midland, Texas, Community Bible Study -- a group to which Bush became a devoted attendee. "It wasn't just a temporary experience for him. He'd changed and all of a sudden studying the Bible was important."

Bush's newfound faith would prove politically important during his father's 1988 presidential campaign, when the elder Bush -- an Episcopalian -- found himself struggling to connect with a group that had recently gained political clout: evangelical Christians. Evangelicals had helped elect Ronald Reagan, the Bush campaign knew, and observers credit George W. Bush with playing a key role in cementing this group's support for his father in 1988.

"If it wasn't for the son, George Bush the father wouldn't have received as much support as he did in the evangelical community," says Wayne Slater, Austin bureau chief of the Dallas Morning News and author of Bush's Brain: How Karl Rove Made George W. Bush Presidential. "George W. Bush reached out to some key evangelical ministers, reassuring them about the values of his father in a way his father, an Episcopalian, never could."

The younger Bush's evangelical credentials would later help him in his campaign for governor of Texas. After a failed run for Congress in the 1970 -- during which he was portrayed as a partying, rich-boy outsider -- Bush's newfound faith enabled him to connect with Texans in a whole new way, observers say.

"I saw George Bush in church settings -- and he was a master," Slater says. "He was marvelously successful in talking their language, reinforcing their values, and appealing successfully to the kinds of people who not only would vote for him, but would tell the neighbors to vote for him. Not only organize phone banks for him, but would call prayer lines and talk about George Bush as a campaigner."

"The Jesus Factor" chronicles Bush's efforts in Texas to allow faith-based groups to access state funding for social service programs -- a policy he would later advance following his election to the White House. And once again, the support of evangelical Christians proved critical to Bush's razor-thin victory.

"The single most reliable predictor of how a person voted in the 2000 election was whether they went to church or to synagogue or mosque at least once a week," says the Southern Baptist Convention's Richard Land. "If [they did], two-thirds of them voted for George Bush."

In "The Jesus Factor," viewers hear from numerous evangelical Christians who say President Bush understands the "heart and soul" of their beliefs and that his post-9/11 speeches comforted a grieving nation. FRONTLINE also speaks to those who feel the president has taken his rhetoric -- and his religion -- too far.

"If we turn religion into a tool for advancing political strategy, we treat it as anything other than a sacred part of life from which we draw values and strength," says Rev. Dr. C. Welton Gaddy, president of The Interfaith Alliance. "Any time that religion has identified itself with a particular political movement or a particular government, religion has been harmed by that."

"The Jesus Factor" concludes by assessing the importance of the evangelical vote to George W. Bush's reelection campaign strategy. "Evangelical Protestants are an absolutely critical part of the Republican base," says Dr. John Green, director of the University of Akron's Bliss Institute of Applied Politics and author of Religion and the Culture Wars. "The first stone in building the wall of re-election are evangelical Protestants."