Problematic preachers weave through the political life of Barack Obama like a coat of many colors, all the way up to and including his inauguration as the 44th U.S. president.
First, firebrand Rev. Jeremiah Wright nearly derailed Obama's fight for the Democratic nomination. The uproar over his remarks from the pulpit such as "God damn America" and the United States being to blame for 9/11, prompted Obama to turn away from his former pastor and give a key speech on race and religion.
Then, the president-elect, who is Christian, chose evangelical minister Rick Warren to give the inaugural invocation. The choice touched off a firestorm of controversy, because Warren has chastised gays from the pulpit at his California Saddleback Church.
As if to open the big tent even more, Obama picked the Bishop V. Gene Robinson, the openly gay Anglican bishop from New Hampshire, to give the invocation at the start of inaugural events at the Lincoln Memorial Sunday. Robinson had previously called Obama's choice of Warren, a supporter of California's ban on gay marriage, a "slap in the face."
Gay rights protesters appeared Sunday at the Ebenezer Baptist Church in Atlanta during Martin Luther King Day festivities to protest Warren's role as a keynote speaker. Over the weekend, about 100 gay rights supporters marched and waved rainbow flags outside Warren's church in Lake Forest, Calif.
"He's being attacked from the left and the right," said Thomas Reese, senior fellow at Woodstock Theological Seminary at Georgetown University. "He's in a tough spot, and I don't know what he'll do."
No advance copy of Warren's inaugural prayer has been made available, and people are wondering whether it will be inclusive or divisive.
"He wants it to be a surprise," said Reese, who will attend the inauguration and the day-after service at the National Cathedral.
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"There used to be a Protestant a Catholic and a Jew," he told ABCNews.com. "Now we get conservatives and liberals. "I think it shows how politicized the religious community has become."
Gay rights advocates are fuming over remarks Warren made to Beliefnet in December, which suggested that if gay marriage were legal, why not incest, polygamy or "an older guy marrying a child?"
Conservative evangelicals criticized Warren for accepting the invitation because of Obama's pro-abortion rights stance, just as they did when the president-elect joined a 2008 forum at Saddleback during the campaign.
But religious and gay leaders are guardedly hopeful that this drama is yet another signal that Obama intends to rely on Lincoln's "team of rivals" approach to hear all points of view.
Both preachers are already softening. When Robinson was named, Warren gushed to The New York Times that the president-elect had "again demonstrated his genuine commitment to bringing all Americans of goodwill together in search of common ground."
"I applaud his desire to be the president of every citizen," said Warren, who has reportedly turned down at least 100 requests for interviews, including one by ABCNews.com.
And Robinson echoed last week, "Frankly, I think it is a magnificent, symbolic statement that Rick Warren and I will be praying for the new president and the nation. I think that's fantastic."
Gay activists said it was "heartening" to know that Robinson was included in the festivities, though his prayer wasn't televised in the live HBO special. But they are still uneasy about Warren's invocation, knowing the "symbolism" and "high profile" of that role.
"We are cautiously optimistic," said Joe Solmonese, president of the Human Rights Campaign, the nation's largest gay rights group. Ultimately, he said, Obama is a friend of the lesbian, gay, bisexual, transgender community. . "The idea is that there is a place at the table for everybody, but at some point we draw the line, when you bring in people with incendiary views that say derogatory things about some Americans," he told ABCNews.com.
Some believe that Warren's centrist views -- supporting a broader agenda for evangelicals than hot-button issues such as abortion and homosexuality -- might shift him to closer association with Obama.
Unlike ideologues like Jerry Falwell or Pat Robertson, Warren has talked about a loving Jesus, taking on causes like climate change, Third World poverty, sex trafficking and HIV/AIDS.
As leader of a 20,000-member mega church, Warren says some issues are non-negotiable: abortion, gay marriage, stem cell research, human cloning and euthanasia.
This tempest in the Christian teapot over the invocation has no precedent.
George Washington never had a prayer at his inaugural. It wasn't until 1937 that the invocation became tradition. Franklin Roosevelt asked a Catholic supporter of the New Deal to join a Protestant in prayer. Later, President Harry Truman added the first rabbi; and Dwight Eisenhower invited a Greek Orthodox minister.
Jimmy Carter cut it back to a Protestant and a Catholic. Ronald Reagan had only a Presbyterian at his first inaugural and later added a Catholic and a Jew. George H. W. Bush and Bill Clinton had Billy Graham, with Clinton adding another Baptist in 1997.
Prayer should be as "inclusive as possible," according to Reese. "The minister leading the prayer should not deny any aspect of his faith to please others, but he need not have every aspect of his faith expressed in his prayer."
The evangelist Graham never mentioned Jesus in his inaugural prayers.
Today Americans are divided over issues like abortion and gay marriage -- rather than the fear that dominated the presidency of John F. Kennedy, a Catholic, "over the Pope to run the government," said Reese.
By extending an invitation to both Warren and Robinson, Obama is "trying to reach out to all sorts of people, and some of them don't like each other," said Reese.
"Warren and Robinson won't find common ground on abortion or gay rights, but Obama can bring them together in concern for the poor or health care or doing something for the victims of AIDS in Africa," he said.
In the two years since Obama has been invoking a message of common ground, a group of disparate voices that includes progressives and evangelicals has been shaping a shared agenda on social issues.
The proposal of shared goals -- "Come Let Us Reason Together Governing Agenda" -- is a call to Obama and to Congress to end the "culture wars."
Spearheaded by the progressive think tank Third Way, it includes religious leaders such as the Rev. Joel C. Hunter and David Gushee, religion scholar Robert P. Jones and the religious group Faith in Public Life.
The agenda calls for agreement on four central issues: reducing abortions by increasing support for pregnant women and new families and adoption; protecting the rights of gays in the workplace, with an exemption for faith-based employers; renouncing torture; and supporting immigration reform.
"We are looking for principles in common: respect for human dignity, the golden rule, pragmatism and optimism are the common threads of the project," said Rachel Laser, director of Third Way's cultural program.
Asking Warren and Robinson to share a role in the inauguration is exactly the kind gesture this country needs, she said.
"Obama is a man of the big tent, letting more people come into the tent of progressive politics, expanding the tent to include someone like Warren and to simultaneously choose someone like the first openly gay bishop," Laser told ABCNews.com.
For Laser, who supports abortion rights and is Jewish, connecting with evangelicals such as the Orlando mega-church pastor Joel Hunter, was daunting but ultimately transforming.
She remembers meeting Hunter, pastor at Northland Church in Orlando, Fla., to show him her project. "Once you foster trust and create an environment that feels safe, it's not as hard as you think," she said.
Hunter, who opposed gay marriage and abortion rights, told Laser, her proposal "touched my heart." He is working on a pastor's manual, with research and Scripture, to help his 12,000-strong parish understand the problems of workplace discrimination for gays, among other issues.
"We believe we are at a watershed moment in the country's history," Hunter said at a press conference announcing the agenda last week.
"The culture wars vilify those who are different from us by treating them as traitors and threats," said Hunter, a one-time president-elect of the Christian Coalition. "We can end the culture wars and both sides can advance without compromising our core basic values. It's a new form of maturity."
As for Warren's invocation, Hunter is hopeful. "I know him, and though I haven't talked to him about it, it'll be a good prayer," he told ABCNews.com.
Like Hunter, theologian Reese is looking for an ecumenical prayer from Warren.
"A prayer that divides the nation is not helpful at this point," said Reese. "The desire is that the largest number of people can say amen and feel they have been included."
"Both sides can get overexcited about this issue, but even most atheists are happy to remain silent," he said.
"If they dropped the prayer, I wouldn't protest," Reese said. "The prayer isn't going to save the country, and not having it isn't going to plunge us into disaster. We have to be reasonable and balanced on this."