on August 02, 2015 at 8:30 AM, updated August 02, 2015 at 8:51 AM
2016 PRESIDENTIAL RACE
Back in 1928, Democrats thought Al Smith had a good chance of winning the presidential election.
Smith, the popular four-term governor of New York, was a reform-minded candidate with a strong political base. But he was also the first Catholic nominee for president.
In the end, Smith's religion sunk his campaign, historians say. Anti-Catholic sentiment, including rumors Smith would answer to the pope as president, swept the country. The Democrat lost badly to Herbert Hoover, failing to even win his home state.
It took more than 30 years for John F. Kennedy to become the first Catholic president. But the Democrat only won after publicly vowing to skeptical voters that he would never take orders from the Vatican.
Fast forward to 2015, when Gov. Chris Christie declared his candidacy for the Republican nomination in a speech that didn't mention his religion. Christie, who was raised Catholic and sends his children to Catholic schools, has barely discussed his faith on the campaign trail.
Jo-Renee Formicola, a Seton Hall University political science professor who studies the separation of church and state, isn't surprised that Christie has been low-key about his faith.
"I don't know that Catholicism is his brand," Formicola said.
Christie is selling himself in the crowded Republican race as the tough-talking governor of New Jersey, Formicola said. He isn't making a push to win votes from the party's Christian evangelicals, who are more likely to rally around former Arkansas Gov. Mike Huckabee, a former Southern Baptist minister, and other candidates who have made their faith a central theme in their campaigns.RELATED: Chris Christie's religion: 7 facts about his Catholic faith
Times have also changed for Catholic candidates, Formicola said. Anti-Catholic sentiment is not as prevalent as it was in the era when Smith and Kennedy had to be defensive about their religion.
"Six of the nine members of the Supreme Court are Catholic. The speaker of the house is Catholic. And the vice president," Formicola said. "Many high government officials are Catholic."
CROWD OF CATHOLICS
Christie is also joining a Republican presidential primary field crowded with Catholics. Of the 17 major candidates in the Republican race, six are Catholic: Christie, Jeb Bush, Bobby Jindal, George Pataki, Marco Rubio and Rick Santorum.
Bush, the former governor of Florida, and Jindal, the governor of Louisiana, both converted to Catholicism.
Bush grew up Episcopalian, like his father, President George H.W. Bush, and his brother, President George W. Bush. Jeb Bush converted to Catholicism 20 years ago, joining his Mexican-American wife, Columba, who was raised Catholic.
Jindal grew up Hindu and converted to Catholicism in college, against the wishes of his Indian immigrant parents.
Rubio also had experience with several religions. The Florida senator, the son of Cuban immigrants, was baptized Catholic. But he was baptized again as a Mormon when his family moved to Las Vegas and converted. Rubio eventually returned to the Catholic Church. But he has also attended a Southern Baptisit megachurch in Miami and often talks about his faith in his campaign events.
Most of the Catholic candidates were asked to comment on their religion after Pope Francis released his encyclical on the environment in June. The pope's statement called global warming a major threat to the earth.
Several candidates said being Catholic does not mean they have to agree with the Vatican on public policy matters.
"I don't get economic policy from my bishops or my cardinal or my pope," Bush said.
OTHER RELIGIONS IN THE RACE
Among the other Republican presidential candidates, there are three Southern Baptists (Huckabee, Ted Cruz and Lindsey Graham), two Presbyterians (Donald Trump and Rand Paul), two nondenominational evangelicals (Rick Perry and Scott Walker), one Anglican (John Kasich), one Methodist (Jim Gilmore) and a Seventh-day Adventist (Ben Carson).
Carly Fiorina is the sole Republican candidate who says she is not a regular church-goer. She was raised Episcopalian, but says she is not currently a member of a church.
Among the presidential candidates for the Democratic nomination, front-runner Hillary Clinton is a Methodist. Her closest competitor, U.S. Sen. Bernie Sanders of Vermont, is Jewish and the sole non-Christian among the presidential candidates. Sanders said in June he is proud to be Jewish, but he is "not particularly religious."
The remaining Democrats in the race include a Catholic (Former Maryland Gov. Martin O'Malley) and an Episcopalian (former Rhode Island Gov. Lincoln Chafee). Former Virginia Sen. Jim Webb, who announced his candidacy in early July, does not identify a religion on his campaign site and has not publicly discussed his faith. But some political sites list him as Protestant.
Voting for atheists
How much a candidate's religion matters to the average voter remains open to debate.
The number of Americans who say they don't belong to any particular religion continues to grow. But the majority of the country still says it is important that their president believes in God, according to a Pew Research survey released last year.
"Just over half (53 percent) say they would be less likely to vote for someone who does not believe in God, while only 5 percent say this would make them more likely to support a candidate," the study said.
Americans would be more likely to vote for a gay candidate or someone who never held elected office before they would vote for someone who is an atheist, the survey found.