Just because President Barack Obama and Mitt Romney mostly have avoided talking religion during this campaign doesn't mean religion won't play a big role in determining the winner of the presidential race. Here are six ways religion's role in the electorate may shape the outcome on Tuesday.
1. Will Catholics pick the winner, again? Representing more than a quarter of the electorate and voting with the winner of the popular vote in every presidential election since at least 1972, Roman Catholics are quintessential swing voters. They encompass such a diverse set of concerns and ethnic groups that some challenge the very idea of a Catholic "voting bloc." However, both campaigns have conducted intense outreach to Catholic voters and have Catholic vice presidential nominees -- Joe Biden and Paul Ryan.
2. Will evangelicals turn out en masse? There's been much speculation about whether white evangelicals, who have accounted for more than a third of Republican votes in recent elections, will turn out in force for Mitt Romney, a Mormon who for years supported abortion and gay rights. Those three facts trouble many evangelical conservatives. Evangelical leaders such as the influential the Rev. Billy Graham have indicated support for Romney (though Graham stopped short of an official endorsement), but will enough evangelicals in the pews turn out to put Romney over the top in swing states such as Ohio and Virginia? Will Obama peel off evangelical votes in states like Colorado, like he did in 2008?
3. Will the "no religion" demographic grow? Americans with no religion are the fastest-growing "religious" group in the country, with a recent Pew survey finding that such voters represent 20% of the population. More than six in 10 of these voters are Democrats. Because they accounted for 12% of the electorate in 2008, they're an important part of the Democratic base. So will they be even more important today? What would that mean for a Democratic Party that has embraced religion since the "values voter" election of 2004?
4. Will Jewish voters be as solidly Democratic as in the past? Obama won a whopping 78% of Jewish voters in 2008, an impressive proportion even among a solidly Democratic segment of the country. But Republicans have made a serious play for Jewish votes, alleging that Obama has been insufficiently supportive of Israeli Prime Minister Benjamin Netanyahu's government. Jewish voters represent just a couple percent of the national electorate, but their numbers are bigger in swing states such as Florida and Pennsylvania.
5. Will black churchgoers be as loyal to Obama as last time? Recent polls show the that the president enjoys 90%-plus support among African-Americans. But many black pastors have criticized Obama for personally backing gay marriage in May. Will that dampen black turnout?
6. Which way will frequent churchgoers go? The United States' large number of churchgoers makes it unique among industrialized nations. People who attend a house of worship at least once a week account for roughly four in 10 voters. President George W. Bush won 60% of those voters in 2004, one of the lynchpins of his victory, and Obama's inroads among such voters helped him win traditionally red states such as Indiana and North Carolina in 2008. The Romney/Ryan ticket has courted this group, saying the Obama White House has attacked religious liberty and American values. Obama's outreach has been more subtle, with the Obama campaign releasing a video of the president discussing his faith over the weekend. The Republican ticket is expected to win this demographic, but the size of its victory may determine whether Romney/Ryan take the White House.