Presumptive GOP presidential nominee John McCain and leading Democratic candidate Barack Obama may both claim the title of Washington consensus builder, but when it comes to the abortion issue, the two have proudly embraced their differences and are expected to tout their contrasting stance to appeal to key constituencies in their party.

Republican John McCain, who has had an uneasy relationship with evangelical Christians in the past, is predicted to use his unbroken pro-life voting record to woo his party’s conservative Christians to his base ahead of November’s general election.

Evangelical Christians make up one in four U.S. adults and are a key support base for the Republican Party.

"Religious conservatives may not be wildly enthusiastic about McCain,” commented Matthew Wilson, a political scientist at Southern Methodist University in Dallas, according to Reuters, “but they can point to his pro-life stance as reason to stay on board.”

Obama, on the other hand, has been extremely supportive of abortion rights, including bills that were controversial even among fellow pro-abortion rights supporters. The Illinois senator supports late-term abortions, which is performed in the later stage of pregnancy when the fetus is more developed, and was opposed to giving babies that survive failed abortions medical care – essentially leaving them to die.

“What we are doing here is to create one more burden on a woman and I can't support that,” Obama had said at the time he voted against the bill that would give medical attention to babies that survive abortions.

Marjorie Dannenfelser, Susan B. Anthony List president, countered, "That’s a living human being he would allow to die because he judges it to be an expendable annoyance,” according to LifeNews.com. “For him again, the unexpected born baby is a punishment and burden – an unnecessary affront to the woman’s decision to abort.”

She noted McCain and his wife Cindy had adopted two children from Bangladesh while visiting Mother Teresa’s orphanage in that country. The couple had not planned on adopting children at the time, but they accepted when two nuns pleaded with them to take the children.

"The McCains’ immediate and generous 'yes' to taking responsibility for two children in an incredibly inconvenient circumstance is revealing – and inspiring," Dannenfelser praised.

As a pro-life advocate, Dannenfelser declared, "No matter who you are, how smart or slow you are, how beautiful or plain you look, how much or little money you have, how healthy and physically fit you are – you are necessary. Your right to life is equal to all others.'"

Recent polls suggest that the new generation of evangelicals, which both McCain and Obama are courting, is even more pro-life than their older counterpart. The Pew Forum on Religion & Public Life found that 70 percent of young white evangelicals between the ages of 18 and 29 said they support legislation that would make it more difficult for woman to obtain an abortion, compared to 55 percent of older white evangelicals.

Some experts expect McCain to do well with this demographic given his strong pro-life record and expressed concern for the climate change problem.

But others fear that if McCain speaks too strongly on the abortion issue he may lose support among independent or centrist voters.

"For the Republicans it is a wedge issue because their right wing is very vocal on it,” said David Epstein, a political scientist at Columbia University, according to Reuters. “To bring it up at all you either risk the wrath of the right or you risk sounding too extremist to the middle."

The abortion and gay “marriage” issues were key topics in the 2004 presidential election when President Bush clinched nearly 80 percent of the votes from white evangelical Protestants. These two issues are again expected to stir debate between the two candidates considering California and New York’s recent legal support of gay “marriage.”