Other surveys suggest the gap is less than has been touted. Recently released data from the American Religious Self-Identification Survey of 2001 indicates that people with a "religious outlook" on life tend to favor the Republicans, people with a "secular outlook" tend to identify as independents, and the Democratic Party holds the middle ground, attracting those with a "somewhat religious outlook."
In this week's Pew poll, 52 percent called the Republican Party "religion-friendly" and 40 percent termed Democrats the same, with 34 percent calling the latter "religion-neutral."
As for how much the candidates discuss their faith, 56 percent said Kerry mentions it "the right amount," and 53 percent credit Bush similarly. The proportion of Americans who criticize the president for discussing faith "too much" rose from 14 to 24 percent in the past year.
The candidates run about even on who would do the best job in improving the nation's moral climate (45 percent for Kerry and 41 percent for Bush).
"This is surprising, as there's been a lot of commentary saying Kerry wasn't holding his own on religion," says Dr. Lugo. "These figures suggest he has made significant headway in convincing voters that he takes his faith seriously."
Lugo says the controversy with Catholic bishops may have actually worked to the senator's advantage. That controversy - in which some bishops said that the pro-choice candidate should not take communion - is one of the stunning developments of the campaign.
"This has turned history on its head," says Charles Haynes, director of education programs at Freedom Forum's First Amendment Center. "In 1960, John Kennedy tried to demonstrate he wasn't too Catholic to be president; now we have a Catholic candidate attempting to prove he is Catholic enough. Today the Catholic vote, as one-quarter of the population, is critical ... and increasingly up for grabs."