WASHINGTON -LRB- CNN -RRB- -- A slim majority of Americans think churches should stay out of politics , according to a new survey . John McCain , the Rev. Rick Warren and Barack Obama together for a CNN broadcast forum on faith . The survey suggests that for the first time in more than a decade , there has been a shift away from the view that religious groups should influence social and political issues . Fifty-two percent of poll respondents said churches should stay quiet , while 46 percent said churches should express political views . The biggest shift has come among Republicans , one of the authors of the poll said . `` Overall , the number of people who say churches should not endorse political candidates is up slightly , but among Republicans it is up 11 points , and among white evangelical Republicans it is up 19 points , '' said Greg Smith , a research fellow at the Pew Forum on Religion & Public Life . `` There is a slight uptick , from 40 percent to 46 percent , among people who are uncomfortable to have politicians talking about religion , but it is up 10 points among Republicans , '' he added . Four years ago , seven out of 10 conservatives approved of religious institutions expressing political views . But five out of 10 conservatives in Thursday 's poll said it was appropriate . It seems that the more important social issues are to conservatives , the more likely they were to say that religion and politics should not mix . Among people who said gay marriage was a very important issue , the number saying houses of worship should keep out of politics doubled , from 25 percent to 50 percent . Among those who said it was not important , the number was essentially unchanged . Respondents were also more likely to say houses of worship should not meddle in politics if they considered the major political parties to be hostile to religion . The new figures bring Republican views into line with those of Democrats and independents . A 14-point gap between Republican and Democratic views on the subject in August 2004 fell to one point in the new survey . But Smith cautioned against reading the survey to mean basic conservative philosophy was changing . `` It appears to be frustration with the contemporary political landscape more than an underlying philosophical shift , '' he said . `` It is not the case the conservatives are uncomfortable with a political role for religion , but we do see increasing discomfort with churches getting involved with politics . '' `` Voting intentions among white evangelicals have not changed at all , '' Smith added . Republican candidate Sen. John McCain `` has a huge lead even among younger evangelicals . '' But social conservatives are lukewarm about McCain as compared to President Bush . Nearly seven out of 10 white evangelical Protestants and conservatives said they supported McCain ; the number was slightly higher for Bush in August 2004 . But four years ago , 57 percent of them said they backed Bush strongly . The number is 28 percent for McCain this year , with 40 percent saying they backed him , but not strongly . The number of people who think religious groups have too much influence over political parties grew -- for both Republicans and Democrats -- as did the percentage of people who are uncomfortable hearing politicians talk about how religious they are . Americans continue to see the Republican Party as more friendly to religion than the Democrats , although the Democrats closed the gap somewhat since reaching a low point in 2006 . Other survey results showed little change from the past . Two out of three Americans continue to say churches should not endorse candidates for president , and most still feel a president should have strong religious beliefs . The survey was conducted by the Pew Research Center for People & the Press and the Pew Forum on Religion & Public Life by interviewing 2,905 adults nationwide by phone between July 31 and August 10 . On Saturday , Obama and McCain answered questions that had religious overtones at a forum hosted by the Rev. Rick Warren . The pastor of Southern California 's Saddleback Church is author of the best-selling book `` The Purpose-Driven Life . '' Asked when life begins , McCain was quick to say `` at the moment of conception . '' McCain 's response was met with huge applause from the audience . `` I have a 25-year pro-life record in the Congress , in the Senate , and as president of the United States , I will be a pro-life president , and this presidency will have pro-life policies , '' he said . When Obama was asked about when life begins , the pro-choice candidate said that decision is `` above my pay grade . '' The response garnered criticism from liberal and conservative thinkers who said Obama tried to dodge the issue . Obama said although he 's pro-choice and supports a woman 's right to abortion , his goal is to reduce the number of abortions in America . `` On this particular issue , if you believe that life begins at conception ... and you are consistent , then I ca n't argue with you on that , '' he said . `` What I can do is say , ` Are there ways we can work together to reduce the number of unwanted pregnancies ? ' ''