In a U.S. election campaign where presidential candidates from both major parties have talked openly about their Christian faith, some non-Christians feel shut out or turned off.
Despite the constitutional separation of church and state, religion plays a big and sometimes decisive role in politics in America, where levels of belief and regular worship are far higher than those in Europe.
"Non-Christians are concerned that they will be excluded from the process," said Ahmed Rehab, a spokesman with the Council on American-Islamic Relations.
"I welcome faith values if they inspire candidates to do good things. But I worry if it is used as a litmus test to include someone in political participation."