President Bush appealed to evangelical Christians in a National Day of Prayer (search) ceremony Thursday that religious networks were broadcasting coast-to-coast.

"At so many crucial points in the life of America, we have been a nation at prayer," Bush said, recalling that Abraham Lincoln (search) had called the country to prayer in the darkest days of the Civil War and that Franklin Roosevelt (search) led U.S. citizens in prayer 60 years ago when U.S. and British troops invaded German-occupied France.

Some academic specialists on religion and politics — and some advocates of a stark division between church and state — suggested the Republicans were using the 53rd annual National Day of Prayer to give the GOP an edge in the November election.

"This event has very strong underpinnings of partisan support for the president, and that's what it's designed to do," said Barry W. Lynn, executive director of Americans United for Separation of Church and State (search). "It's not like he is ignoring other religious groups, but he knows that this day is the one where he signals 'I am an evangelical Christian. Remember that in November.'"

Christian conservatives overwhelmingly supported Bush over Al Gore in 2000, but the Bush-Cheney campaign wants to lure even more evangelical Christians to the polls in November.

During Thursday's event, one of thousands of National Day of Prayer observances held across America, Bush recognized Rabbi Tzvi Hersh Weinreb of the Orthodox Union of Jews, other religious leaders as well as conservative Oliver North, an Iran-contra figure turned radio talk show host who is honorary chairman of this year's National Day of Prayer.

"This is stroke-the-base, stroke-the-base, stroke-the-base," said John Kenneth White, who teaches in the politics department at Catholic University of America and has written about values that divide the country.

In some ways, Bush is like former President Carter, wearing his faith on his sleeve, he said. What's different between 1976 and now is that the country is extraordinarily polarized on issues of marriage, race and religion, he said.

"It's not the old Protestant versus Catholic gap, but one between those who attend church regularly versus those who seldom or never go," White said. "Bush hasn't divided us, but I think this prayer event serves to reinforce that existing division."

Bush's appearance at the prayer event in the East Room came just minutes after he apologized for the mistreatment of Iraqi prisoners by U.S. soldiers — a statement he made standing side-by-side with the king of Jordan, part of the Arab community outraged by photographs taken of the abuse.

"We cannot be neutral in the face of injustice or cruelty or evil," Bush said in his prayer day remarks, without specifically referring to the war in Iraq. "God is not on the side of any nation, yet we know he is on the side of justice. And it is the deepest strength of America that from the hour of our founding, we have chosen justice as our goal."

"Our greatest failures as a nation have come when we lost sight of that goal: in slavery, in segregation, and in every wrong that has denied the value and dignity of life. Our finest moments have come when we have faithfully served the cause of justice for our own citizens and for the people of other lands."

The president nodded his head as soloist Beth Cram Porter gave a moving, solemn rendition of a gospel song titled, "There's a Balm in Giliad." But the event, filled with references to U.S. troops in Iraq and Afghanistan, was not without levity.

Barry Black, the chaplain of the Senate, recalled how his mother used to give him a nickel for every Bible verse he memorized. Then he added: "She eventually put me on a flat rate."