Obama was a community organizer trying to build support for his group on the South Side of Chicago, and a friendly minister at another church had suggested he'd have more luck with black clergy if he joined a congregation himself.
Obama ended up joining, a story he tells in his memoirs, and later was influenced enough by Wright to derive the title of a subsequent book, "The Audacity of Hope," from one of the pastor's sermons.
But despite the warning, the association did not seem to be a terribly risky one for Obama, given the arc of the career he was beginning to craft even then.
He was building his résumé as a street-savvy community organizer while also applying for admission to law school. Within the walls of Trinity he found a connection to the African-American community he'd lacked as a child raised by his white mother and grandparents, an important cultural marker for a biracial candidate who later would try to appeal to black and white voters alike.
He'd share church membership with some of Chicago's influential thinkers and leaders, among them lawmakers, judges and Oprah Winfrey. And in Wright he would find an inspirational messenger—not to mention one of Chicago's most prominent black ministers—in a setting where church affiliation can form part of a person's political pedigree.
For someone thinking of running for mayor, governor, senator or any statewide office, being part of Trinity would likely be an asset.
On the national stage, that asset has become a liability. Obama's association with Wright has sent his once-soaring presidential campaign into a strategic tailspin, thanks to controversial statements from old sermons the minister publicly repeated at high volume last week.
As Wright's remarks have filled the airwaves, many have wondered why Obama remained a member at Trinity for so many years. He says he wasn't present at church for some of the most outrageous comments, yet there were signs that Obama and his campaign were aware that an association with Wright could be controversial. Obama last year in effect disinvited Wright from giving an invocation when he announced in Springfield he was running for president.
Some of Wright's more controversial sermons burst into public view in March, and Wright's appearance at the National Press Club last week seemed to reveal a strong provocative streak. Wright voiced anger about what he depicted as an attack on the black church as a whole.
Why Obama stayed"My thinking is, how can you sit in a congregation for 20 years and not pick up on some of this?" asked Lois Capps, a Linden, N.C., voter who attended a Bill Clinton rally near her home last week, voicing one of the most persistent questions in the Wright story.
Obama hasn't directly addressed the question of why he has stayed at Trinity, though he may have been gearing up to do so in a lengthy Sunday interview on NBC's "Meet the Press."
But in Chicago, the choice to attend Trinity for so long is a little less of a puzzle, given Obama and Wright's shared history on the city's South Side and the spiritual and cultural haven the church and pastor offered the aspiring politician.
Membership at Trinity is often taken as a progressive credential, a sign that a person is attuned to issues of social justice and equality and supportive of issues important to its gay and lesbian members.
"Rev. Wright is more sophisticated intellectually than many pastors," said Kwame Raoul, the state senator who took Obama's place in the Illinois legislature and who is a member at Trinity. "He's well-read, he takes the theology seriously. He doesn't just make quick references to the Bible but offers a very deep analysis and an application to current events."
In an interview in early 2007, Obama said Wright had affected his politics by nurturing his connection to the historically black church and how he understands the obligations of his faith.
"He's been somebody who has helped me feel comfortable with some of my doubts when it comes to faith and how to work those through," Obama said at the time. "His scholarship is very rigorous, and his sense of social justice is very keen."
Theologically, Trinity has always stood apart from the constellation of black churches in Chicago, many of which offer a more socially conservative message. Wright questions the common sense of Scripture, ordains women, defends gay rights and preaches a theology of black liberation, which seeks to make the gospel relevant to the black experience.