The Texas governor, now a Republican presidential candidate, held a prayer rally for tens of thousands, read from the Bible, invoked Christ and broadcast the whole event on the Web.
There was no symbolic nod to other American faiths. No rabbi or Roman Catholic priest was among the evangelical speakers. It was a rare, full-on embrace of one religious tradition in the glare of a presidential contest.
Looks like another raucous season for religion and politics.
It used to be simpler. Protestants were the majority, and candidates could show their piety just by attending church.
Now, politicians are navigating a landscape in which rifts over faith and policy have become chasms. An outlook that appeals to one group enrages another. Campaigns are desperate to find language generic enough for a broad constituency that also conveys an unshakable faith.
There is no avoiding the minefield, especially with early primaries in Iowa and South Carolina, where evangelical voters are so influential.
Nationally, more than 70 percent of Republicans and more than half of Democrats say it's somewhat or very important that a presidential candidate have very strong religious beliefs, according to the Public Religion Research Institute.
In 1960, John F. Kennedy could blunt Protestant fears about his Catholicism by calling his religion private. After four decades of culture wars and Christian right activism, the Kennedy strategy no longer works.
Politicians are evaluated not only by what church they attend, but also by what their congregation teaches and what their pastor says on Sundays.
"Candidates often have to make tough choices about their religion -- whether to talk about it, what to say about it and even what to do about it -- such as leaving a church," said John Green, director of the Bliss Institute of Applied Politics at the University of Akron, Ohio. "These tensions are quite strong among Republicans as the presidential nomination contest heats up, partly because of religious disagreements among key constituencies, but partly because of differences in issue priorities -- economic versus social issues."
The current campaign began with two cautionary tales fresh in the minds of political strategists:
In 2008, candidate Barack Obama broke ties with his Chicago pastor, the Rev. Jeremiah Wright, after videos surfaced of Wright sermonizing that U.S. foreign policy played a role in the Sept. 11 attacks. "America's chickens are coming home to roost," Wright said. Obama was so close with Wright that the Democrat took the title of his 2006 book, "The Audacity of Hope," from one of the pastor's sermons.
Republican Mitt Romney was the other example. The former Massachusetts governor had struggled to address concerns about being Mormon despite a major faith-and-values speech in 2007 in Texas.
He quoted the New Testament and declared his belief in Jesus; many Christian denominations don't consider Mormons to be Christian.
He commended the deep faith of the Founding Fathers and decried secularism. Like Kennedy, he promised that "no authorities of my church, or of any other church for that matter, will ever exert influence on presidential decisions." Yet, polls continued to show an unwillingness to vote for a Mormon, especially among white evangelicals.
"That speech probably drew more attention to his Mormonism than it was worth," said Ed Kilgore, a former policy director at the centrist Democratic Leadership Council who oversaw programs that urged Democrats to talk about the values behind their policies. "It raised a lot of questions and didn't really resolve them."
Romney is once again running for president. He has barely discussed his religion so far.
Politicians are facing complex questions on religious doctrine, prompted in many cases by their own attempts at highlighting their faith.
Republican Michele Bachmann of Minnesota has been asked to explain a statement she made in the context of her 2006 congressional campaign, that she submits to the authority of her husband.
The teaching is based on Ephesians 5:21-23 and other Bible verses. Evangelicals say the doctrine is about sacrificial love, the way Christ sacrificed himself for the church. A wife should put her husband's needs first and the husband should serve his wife, although some Christian conservatives view the teaching as a license to control their wives.
In a recent GOP debate, Bachmann was asked to explain whether, as president, she would submit to her husband's authority. The audience booed the question. Bachmann was tight-lipped as she listened, then thanked the questioner and said that to her, submission means that she and her husband respect each other.
Bachmann also found herself in the midst of a row about the Reformation.
News outlets reported that the Wisconsin Evangelical Lutheran Synod, the tiny denomination she formally left around the time she launched her presidential campaign, said on its website that the papacy is the anti-Christ.
The Lutheran World Federation agreed in a 1999 joint statement with the Vatican to drop the doctrinal condemnation. The Wisconsin Synod is not a member of the federation.
Bachmann insisted she was not anti-Catholic.
Perry largely dismissed the outcry over his July prayer rally, held the week before he announced he was running for president.
The event was his idea and was financed by the American Family Association, a Tupelo, Miss.-based group whose policy director believes that freedom of religion applies only to Christians.
Among the supporters were well-known Christian conservative leaders such as the Rev. Richard Land of the Southern Baptist Convention and Focus on the Family founder James Dobson.
Other endorsers were Pastor John Hagee, a Christian Zionist who had called the Catholic Church "the great whore," though he later apologized for the statement. Activist and historian David Barton, who argues that the United States was founded to be a Christian nation, was another backer.
Religion was so in the foreground in the 2008 presidential race that for their first appearance on the same stage after their party conventions, Obama and Sen. John McCain, R-Ariz., agreed to an event at a church where they would be interviewed by a minister.
The Rev. Rick Warren, founder of Saddleback Church in California, asked the candidates what faith in Jesus meant to them and at what point a baby gains human rights.
For the latter question, McCain answered, "At the moment of conception." Obama joked that the question was "above my pay grade," then went on to explain the moral thinking behind his support for abortion rights. Obama soon after apologized for the way he started his answer, saying he was too flip.
"These folks are not professional theologians and, except in a few cases like Huckabee, they haven't been to seminary," said Gary Smith, author of "Faith & the Presidency" and a historian at Grove City College, a Christian school in Pennsylvania. Mike Huckabee, the former Arkansas governor and 2008 GOP presidential hopeful, is a Southern Baptist minister.
"Most of them haven't had more education about the relationship between Christianity and politics than the average person on the street," Smith said. "While they have their own personal faith, it isn't usually well informed by history and theology."
Voters have started pushing for specifics because they no longer consider belief separate from action and faith unrelated to policymaking, said Kathleen Flake, who specializes in American religious history at Vanderbilt University. The nation's Catholic bishops, more vocal than ever on the duty of Catholic lawmakers to follow church teaching, underscored that way of thinking. Bishops have said repeatedly that a true Catholic cannot support any policy that allows abortion.
"The voting public no longer believes, as they did as late as the 1950s, that religion was about what you thought and not what you did," Flake said.
The trend started with Democrat Jimmy Carter, who in 1976 said at a campaign event that he was a born-again Christian.
Although Carter's liberal-leaning policies would ultimately alienate many evangelicals, his declaration sparked Christian conservative involvement in politics and set the stage for deeper scrutiny of candidates' faith. Politicians and their strategists began preparing a standard response to what became known as the "born-again question," which was asked not only in private meetings with Christian conservatives, but also in presidential debates.
Doug Wead, an adviser on evangelicals to the presidential campaign of Republican George H.W. Bush, recalled a meeting between the then-vice president and a group of televangelists, who asked what Bush would say if he "were to appear suddenly at the Pearly Gates," and St. Peter asked why the politician should be allowed into heaven.
Bush, a mainline Protestant, answered, "I would tell him I'm a good person. I tried my best to do the right things," Wead said.
"I thought, `Oh, no,"' said Wead. Evangelicals don't believe salvation can be earned. They would expect true Christians to say they would enter heaven because Jesus died for their sins and they accept Christ as savior.
Today, Wead advises Republican presidential candidate Ron Paul, a libertarian and Texas congressman. Paul has issued a statement of faith saying that he was raised as a Christian and accepts Christ as his personal savior.
For the 2012 race, analysts predict that Romney will eventually have to talk about how his faith would influence the way he governs.
Former Utah Gov. Jon Huntsman, a 2012 contender, is perhaps the first presidential candidate claiming the "spiritual, not religious" mantle.
He was raised Mormon but said he is not very active in The Church of Jesus Christ of Latter-day Saints. Huntsman's wife, Mary Kaye, who was raised Episcopalian, told Vogue magazine, "We are a family that combines two, and it works for us."
Religion scholars have noted the growing popularity of the "spiritual, not religious" approach to faith, so Huntsman's outlook would resonate with many Americans, although people who hold this view are hardly an organized political group.
Some Democrats are trying to persuade Obama to return to the religious language he used in the 2008 race as one way to clarify his values and inspire voters, even though the strategy will raise questions about Wright and about the misperception among some voters that the president is Muslim.
Surveys have found that around 40 percent of voters say they don't know his religion.
"For the first time, we're not only interested in whether someone is religious, which is essentially a question of, `Do you have a morality that the voter can identify with?"' Flake said. "It appears that there's a significant portion of the electorate that's interested in what the particular theology of the candidate is. Do they believe in Jesus? If so, what kind of Jesus do you believe in?"