PALO ALTO, Calif. — A speaking invitation extended to Senator Clinton by one of the nation’s most prominent evangelical preachers and authors, Rick Warren, is drawing fire from conservative Christian groups critical of the Democratic presidential candidate’s views on abortion and other social issues. Mrs. Clinton is to speak this afternoon to a conference on AIDS and HIV issues to be held at Pastor Warren’s Saddleback Church in Lake Forest, Calif.

“I think it’s a big mistake for Pastor Warren to invite Senator Clinton to speak at an evangelical church,” Timothy Wildmon of the American Family Association said. “If Senator Clinton is elected president, she will appoint ACLU lawyers to be federal judges, including to the Supreme Court. She also will press for expansion of hate crimes laws. She will do things that will threaten the rights of Rick Warren’s very church to speak and talk.”

“The first thing that comes to mind is that is a disservice to that congregation,” the executive director of the Eagle Forum, Jessica Echard. Pastor Warren should not give a platform to Mrs. Clinton because her views on abortion are at odds with core values of the evangelical movement, she said.

“Fighting AIDS in Africa is a worthy endeavor, but skipping over the fact that we’re killing babies in the U.S.? Most evangelical people are not comfortable turning a blind eye to that,” Ms. Echard said.

“Inviting politicians from different perspectives to the summit is not a political decision—it is a humanitarian and Christian action,” Pastor Warren said in a press release last week. “When millions are dying each year, we’re interested in lives not labels.”

Saddleback is one of the largest churches in America, claiming attendance of more than 20,000 worshippers each week. Pastor Warren’s 2002 book, “A Purpose Driven Life,” sold more than 25 million copies.

The minister was vaulted into the national limelight in earnest in 2005 when a young mother taken hostage in Georgia, Ashley Smith, said she persuaded her captor to release her by reading him passages from the runaway bestseller. Pastor Warren, who favors Hawaiian shirts, is regarded skeptically by some evangelical leaders who see him as too open to “new age” practices.

Senator Obama of Illinois, spoke at the gathering last year. More than a dozen conservative religious and political leaders signed a letter in an unsuccessful attempt to urge Pastor Warren to rescind the invitation to Mr. Obama.

A spokesman for Mrs. Clinton offered no comment for this article.