When Barack Obama and John McCain offered their sharply divergent views on abortion this weekend at an Orange County church, it was a rare chance to hear the presidential rivals address one of the most contentious issues in American politics.
Each has sought to steer clear of the often fierce disputes between their parties on abortion, relegating it to the low ranks of campaign quarrels.
With the election being fought largely over centrist voters, the White House hopefuls have tried to reach out to those who disagree with their views on abortion.
Obama, a Democrat who supports abortion rights but reminded the audience at Saddleback Church that he wanted to make the procedure less common, has managed to make accommodations to abortion opponents without complaints from his party's base.
But McCain, who opposes abortion, has ignited new tensions with the Republican Party's conservative wing by trying to mollify those who want it to remain legal.
Despite their efforts to downplay the issue, McCain and Obama almost certainly would steer the country in opposite directions on abortion through their appointments to the Supreme Court, which may be just a conservative vote short of overturning Roe vs. Wade, the 1973 decision that established a constitutional right to abortion.
"Whoever is elected president will have the power to fundamentally transform the future of abortion politics," said Cynthia Daniels, a political scientist at Rutgers University.
In navigating abortion politics, McCain faces a much tougher climate than Obama.
The Arizona senator sparked threats of a conservative revolt last week by saying he would not rule out Tom Ridge as a running mate just because the former Pennsylvania governor "happens to be pro-choice."
"If he selects Tom Ridge, he's going to inflict a mortal wound on his campaign," said Richard Land, who heads the public policy arm of the Southern Baptist Convention.
McCain's latest conflict with the religious right underscored his long-standing trouble inspiring enthusiasm among social conservatives. On Saturday, McCain sought to ease the friction by assuring abortion opponents that he would take their side in the White House.
"I will be a pro-life president, and this presidency will have pro-life policies," he told Pastor Rick Warren during the nationally televised forum at Warren's evangelical church.
Obama, on the other hand, faced no backlash last week when he reached out to voters who might be put off by his support for abortion rights. The Illinois senator's party put out a revamped platform with explicit language intended to appeal to those voters. It pledged support not just for abortion rights but also for "a woman's decision to have a child."
The language, up for approval next week at the Democratic National Convention, comes as Obama is trying to erode the Republican advantage among white evangelical voters.
"It's a step in the right direction," said the Rev. Joel C. Hunter, a Republican pastor of a central Florida mega-church. Hunter was one of several evangelical leaders who offered advice to Democrats drafting the platform, which abortion rights groups also applauded.
At the Saddleback forum, Obama took credit for pushing the platform change, saying the nation's goal should be to reduce the number of abortions. While sidestepping the question of when a baby should get human rights, saying it was "above my pay grade," Obama reminded the audience that he supported some limits on late-term abortion.
"One of the things that I've always said is that on this particular issue, if you believe that life begins at conception, then -- and you are consistent in that belief -- then I can't argue with you on that because that is a core issue of faith for you," he said. "What I can do is say: Are there ways that we can work together to reduce the number of unwanted pregnancies?"
In another nod to antiabortion voters, Obama has given a prime-time speaking slot at the convention to Sen. Bob Casey Jr., a Pennsylvania Democrat known for his opposition to abortion. For a party trying to widen its base, the move's symbolism was clear. In 1992, the Democrats denied a speaking role at their convention to the senator's father, the late Gov. Robert Casey, who was also an outspoken abortion opponent.
So far -- with the exception of their back-to-back appearances at Saddleback Church -- McCain and Obama have largely played down abortion, opting to engage more forcefully on matters that voters rank as more important, such as the economy and Iraq.
"The luxury of worrying about social issues disappears when you've got a war on or you've got an economy in the tank," said political scientist Gary Jacobson of UC San Diego.
This is a departure from the last two presidential elections. In 2000 and 2004, George W. Bush used his opposition to abortion rights as a key tool to boost turnout of conservative voters. This year, McCain has focused more on winning moderates and independents.