The conventional wisdom in American politics has long been that someone who is not religious cannot be elected president of the United States. Most Americans have consistently said that it is important to them that the president have strong religious beliefs. And a new Pew Research Center survey finds that being an atheist remains one of the biggest liabilities that a presidential candidate can have; fully half of American adults say they would be less likely to vote for a hypothetical presidential candidate who does not believe in God, while just 6% say they would be more likely to vote for a nonbeliever.

Among presidential candidates, Trump seen as least religiousOn the other hand, the share of American adults who say they would be less likely to vote for an atheist candidate has been declining over time. Moreover, one of the candidates who is widely viewed by Republicans as a potentially “good” or “great” president, Donald Trump, is not widely viewed as a religious person, even by those in his own party. And on the Democratic side, the share of Americans who say Hillary Clinton is not a religious person now stands at 43%, which is sharply higher than it was in the summer of 2007, when she was seeking the presidential nomination for the first time.

These are among the key findings of a new Pew Research Center survey conducted Jan. 7-14, 2016, on landlines and cellphones among a national sample of 2,009 adults. This is the latest in a long line of research the Center has conducted on the role of religion in presidential campaigns. In 2012, for instance, polling found that Mitt Romney’s Mormon faith was a potentially important factor in the Republican primaries but was not likely to play a major role in determining the outcome of the general election. In the run-up to the 2008 campaign, voters who saw presidential candidates as at least “somewhat” religious expressed more favorable views of those candidates; but the Center’s research also showed that White House contenders need not be seen as very religious to be broadly acceptable to the voting public. And in 2004, a majority of the U.S. public thought it was improper for the Catholic Church to deny communion to pro-choice politicians like John Kerry.

Half of adults say they would be less likely to support atheist for president

The new survey confirms that being an atheist continues to be one of the biggest perceived shortcomings a hypothetical presidential candidate could have, with 51% of adults saying they would be less likely to vote for a presidential candidate who does not believe in God. Indeed, in the eyes of the public, being a nonbeliever remains a bigger drawback than having had an extramarital affair (37% say they would be less likely to support a candidate who had been unfaithful), having had personal financial troubles (41% say they would be less likely to support a candidate who had had financial struggles), or having used marijuana in the past (20% would be less likely to support a former pot smoker).

Two-thirds of Republicans say it is important to have a president who shares their religious beliefsThe study also shows that having a president who shares their religious beliefs is important to many Americans, with about half of U.S. adults saying it is “very important” (27%) or “somewhat important” (24%) to have someone in the White House who shares their religious perspective. This view is particularly common among Republicans, among whom roughly two-thirds say it is at least “somewhat important” to them that the president share their religious beliefs.

Fewer Americans would be deterred by atheist presidential candidate At the same time, the new survey also finds that the share of Americans who have reservations about voting for an atheist president has been declining over time. As recently as 2007, more than six-in-ten Americans said they would be less likely to support an atheist presidential candidate, while just 51% express this view today. Over this period, the share who say a candidate’s lack of belief would not be a factor in how they vote has been growing.

The new survey finds that Trump is widely viewed as a potentially “good” or “great” president by GOP voters in spite of the fact that, compared with other leading candidates, relatively few Republicans think Trump is a particularly religious person. Overall, 44% of Republicans and those who lean toward the Republican Party say Trump is a “very religious” (5%) or “somewhat religious” (39%) person, while 47% say he is “not too religious” or “not at all religious.” By contrast, fully eight-in-ten Republicans say they think Ben Carson is a religious person, three-quarters view Ted Cruz as a religious person, and seven-in-ten say the same about Marco Rubio.

Compared with Carson, Cruz and Rubio, fewer GOP voters see Trump as a religious person

Being seen as a religious person is generally an asset for candidates; people who think a candidate is a religious person tend to be more likely to see that candidate as a potentially good president. But many Republicans think Trump would be a good president despite his perceived lack of religiousness. Of the 56% of GOP voters who think Trump would be a good or great president, a substantial minority of them (17% of Republican registered voters overall) say they think Trump is not religious. The pattern is very different for the other leading GOP candidates; virtually all Republicans who think Cruz, Rubio and Carson would be successful presidents (and who express a view about their religiousness) also say they view those candidates as at least somewhat religious. Just 2% of GOP voters think Rubio would be a good president and that he is not particularly religious, with just 1% saying the same about Cruz and Carson.

Many republicans say Trump would be good or great president despite not being religious; few say same about other candidates

The new survey shows that among religious groups, fully half of white evangelical Protestant voters (including both Republicans and those who identify with the Democratic Party or as political independents) think Trump would make a “good” or a “great” president. Evangelicals – who are among the most reliably Republican religious constituencies in the electorate – express a similar degree of confidence that Carson and Cruz would be successful presidents.1 Evangelical voters are less convinced that other Republican candidates would be good presidents. And few evangelical voters think Bernie Sanders (16%) or Clinton (15%) would be good presidents.

Half of evangelical voters think Carson, Trump and Cruz would be good presidentsWhile there are about as many evangelicals who think Trump would be a “good” or “great” president as say the same about Cruz and Carson, there also is considerably more wariness about Trump than about Carson or Cruz; three-in-ten evangelicals (29%) say Trump would be a “poor” or “terrible” president, which is roughly twice the share who say this about either Cruz or Carson.

On the Democratic side, the view that Sanders and Clinton would be good presidents is most common among two reliably Democratic religious constituencies – black Protestants and religiously unaffiliated voters (i.e., religious “nones”). Fully half of religiously unaffiliated registered voters (51%) think Sanders would be a successful president, while four-in-ten (42%) think Clinton would be a good or great president. Among black Protestant voters, about six-in-ten (62%) think Clinton will be a “good” or a “great” president, while 36% say this about Sanders. Among both groups (religious “nones” and black Protestants), just 15% or fewer think any of the Republican candidates would be good presidents. (More information on religious groups’ views of which candidates would be successful presidents is available in Chapter 1 and in the detailed tables included at the end of this report.)

Half of religious 'nones' say Sanders would be good president; most black Protestants say same about Clinton

More people view Clinton as “very” or “somewhat” religious than say the same about Sanders. This is true among both the public as a whole (48% vs. 40%) and those who identify with or lean toward the Democratic Party (65% vs. 47%). But the share of Americans who say Hillary Clinton is “not too” or “not at all” religious has risen sharply since 2007. At that time, during the run-up to the campaign for the 2008 Democratic nomination, 24% of adults said Clinton was “not too” or “not at all” religious; today, 43% say she is not religious. Over this period, the share of Americans expressing no opinion about Clinton’s religiousness declined from 22% to 9%, while the share describing her as “very” or “somewhat” religious ticked down from 53% to 48%. The uptick in the view that Clinton is not particularly religious is most pronounced among Republicans, but also seen among Democrats. (See Chapter 1 for more details.)

Most say religion is losing influence on American lifeWhen asked about their view of religion’s influence in American society, the survey finds that the large majority of U.S. adults continue to believe that religion is losing influence. And most who hold this view – about half of all U.S. adults – say they think religion’s declining influence is a bad thing for American society.

The survey also shows that four-in-ten Americans think there has been too little expression of religious faith and prayer by political leaders, compared with roughly a quarter (27%) who say there has been too much religious talk by politicians. These figures have not changed much since 2014, but they are considerably different from the results of a survey taken at a similar point in the 2012 presidential election cycle. At that time, there were more people who thought there was too much religious discussion (38%) than who said there wasn’t enough (30%).

Other key findings include:

  • Candidates are viewed as religious by more people in their own party than the opposing party. The biggest partisan gap on these questions is seen in views about Hillary Clinton; two-thirds of Democrats say she is “very” or “somewhat” religious, while two-thirds of Republicans express the opposite view, saying that she is “not too” or “not at all” religious.
  • Like Hillary Clinton, Barack Obama is also seen as less religious today than in 2007; about one-third of adults (35%) now say Obama is “not too” or “not at all” religious, up from 9% in 2007.
  • Half of Americans (51%) believe religious conservatives have too much control over the GOP, and more than four-in-ten (44%) think that liberals who are not religious have too much control over the Democratic Party. Partisans are deeply divided on this question. Two-thirds of Democrats say the GOP has been co-opted by religious conservatives, while most Republicans reject this notion. Conversely, two-thirds of Republicans believe that secular liberals have too much power in the Democratic Party, while two-thirds of Democrats disagree.
  • One-quarter of adults (26%) say they would be less likely to vote for a gay or lesbian presidential candidate, while 4% say they would be more likely to support such a candidate and seven-in-ten (69%) say it would make no difference to their vote. Since 2007, the share of Americans who say a candidate’s sexual orientation would not matter in their vote has been steadily rising, while the share who say they would be less likely to support a gay or lesbian candidate has been declining.
  • There are more than twice as many Republicans who say they would be less likely to support a presidential candidate who has been an elected official in Washington for many years as who would be more likely to support such a candidate (44% vs. 18%). Among Democrats, the balance of opinion leans in the opposite direction; 27% see extensive Washington experience as a positive, compared with 19% who see it as a liability.