DES MOINES, Iowa — If there is a single issue that all the candidates agree upon in the 2008 presidential race, it might be the importance of their faith in God.

Former Arkansas Gov. Mike Huckabee says it "defines me." Sen. Barack Obama, D-Ill., says it guides "my own values and my own beliefs."

In the most-watched speech of former Massachusetts Gov. Mitt Romney’s campaign, titled "Faith in America," he pledged that faith “would inform my presidency, if I were elected."

Such statements are hallmarks of this presidential primary season in Iowa, South Carolina and, to a lesser extent, New Hampshire: Rarely have religious beliefs played such an important role in choosing the next leader of the United States.

"This is unprecedented in modern political history," said Kevin Coe, a University of Illinois doctoral candidate who studies politicians' religious statements. “People might say that religion and politics have always mixed in politics, and that’s true, but there are real changes.

"It’s not a ceremonial declaration of God. What you see instead is the use of God as kind of a political weapon that doesn’t just celebrate faith, but is used to identify enemies and to try to position ideas against each other," said Coe, who co-wrote the book The God Strategy with professor David Domke of the University

of Washington.

In the final days of campaigning before Thursday’s Iowa caucuses, faith will surely remain a topic.

One reason is Iowa itself, where the electorate is especially religious, and not just the Republicans — Democrats here also list faith as an important criterion in selecting a president.

That’s a fact that Democratic candidates previously ignored at their peril, said Gordon Fischer, the chairman of the Iowa Democratic Party from 2002

to 2004.