Former Arkansas Gov. Mike Huckabee (R) and top evangelical leaders will join forces next week to amplify issues such as abortion, same-sex marriage and stem-cell research in the race for the White House.

Huckabee, Family Research Council President Tony Perkins, and Lou Engle, the leader of The Call, a young adult movement, plan to hold a news conference Friday calling on Sens. John McCain (R-Ariz.) and Barack Obama (D-Ill.) to spend more time talking about issues that matter to evangelical voters.

The event will take place Aug. 16, the same day McCain and Obama will make their first joint general election campaign appearance. The presidential contenders will share the stage for a few minutes at a forum at Saddleback Church in Orange County, Calif., the 20,000-strong mega-church of Rick Warren. Warren is a pastor and the best-selling author of The Purpose-Driven Life.

Warren will interview each candidate for an hour separately, but the two will appear on stage for a few minutes together. The topic will be “compassion and leadership.”

Engle admits that the press conference and rally on the mall are designed to counter the Warren candidate interviews, which he predicted would be more politically correct and focus more on “what the church is for rather than what it is against.”

Engle, a vehement opponent of abortion rights, said the goal of the rally on the mall is to “drive the issue of abortion like a wedge into the soul of the nation.”

Social conservatives, disappointed with Huckabee’s loss in the GOP presidential primary, still are wary of McCain and some of the policies and actions he has taken in the Senate. Perkins and others have warned that McCain has yet to assuage their concerns, and the lack of excitement in the evangelical community about McCain’s candidacy could cost him the same key votes that helped carry President Bush across the finish line in 2000 and 2004.

Evangelical leaders are urging McCain, a lifelong opponent of abortion rights, to commit to pushing a constitutional amendment on gay marriage. Social conservative leaders also want him to take a firm position on banning federal funding for stem-cell research.

“I don’t trust John McCain,” Engle said.

McCain’s pledge to appoint strong anti-abortion judges like Supreme Court Justices John Roberts and Samuel Alito does nothing to alleviate Engle’s worries.

“Ronald Reagan promised that and he gave us some of the worst judges we have today,” he said.

McCain’s membership in the bipartisan “Gang of 14,” a group of senators who worked to accommodate each other on judicial appointments, is a major concern, Engle said.

The issue of stem-cell research has put McCain in direct opposition to many social conservatives’ anti-abortion fervor.

In the late 1990s, McCain’s political mentor and friend, former Arizona Democratic Rep. Morris Udall, was in the hospital suffering from Parkinson’s disease while the Senate engaged in one of its earliest debates on stem-cell research. Lawmakers took up a bill that would overturn the ban on research using fetal tissue from elective abortions.

Udall’s daughter, Anne, personally lobbied McCain to support the stem-cell bill. In the end, McCain voted in favor of the research.

Engle said Sen. Sam Brownback (R-Kan.), one of the most vocal abortion opponents in Congress and a supporter of the GOP presidential candidate, has discussed the matter with McCain and has tried to convince him that alternatives to stem cells from embryos have shown promising advances in treating incurable diseases.

In 2006, McCain voted for two stem-cell research bills – one that would offer federal support for research using embryos slated for destruction by fertility clinics, which Bush vetoed, and another that would ban the creation of embryos for research. Obama voted in favor of the same bills.

McCain, however, has been more vocal about his interest in funding adult stem-cell research that uses new ISP cells – adult stems cells that have been turned back into their embryonic state. Scientists argue that this process is far more challenging and less flexible.

Engle disagrees with some Christian leaders such as Perkins, who has predicted that many evangelicals will stay home in November if McCain does not do more to reach out to them. He worries, however, that Obama’s positive rhetoric could appeal to large numbers of Christians despite his record on abortion.

“I think a lot of Christians are already being courted by him and are being taken in by his charisma and his communication,” Engle said. “When he says he wants to make abortion rare but has a 100 percent voting record on abortion [from NARAL Pro-Choice America for his U.S. Senate votes], it’s the talk of a politician.”

“This is a different kind of Christianity,” Engle continued. “We cannot compromise essential truths. Many in the church have been deceived by double talk. We know that Obama will appoint judges that will throw the doors open to the kind of freedom that is not founded in the scriptures.”