In the week after Barack Obama and John McCain explored the connections between their beliefs and political convictions in one of America's biggest megachurches, a new poll shows that a slight majority of the public now thinks that churches and other houses of worship should keep out of politics.

The Pew Research Center and the Pew Forum on Religion and Public Life say that this is the first time since they began asking the question more than 10 years ago that a majority has not been in favor of religious institutions speaking out on political and social issues.

Surprisingly, the biggest change of heart has occurred among conservatives. Four years ago, only 30 percent thought religion should keep its nose out of politics. Now, a full half does. That brings self-identified Republicans more closely in line with Democrats (51 percent in 2004, 52 percent in 2008) on the question.

The public in general is also now more uncomfortable with politicians who talk about their religious convictions, with the biggest shift again taking place among Republicans.