AMERICA is not an easy place for atheists. Religion pervades the public sphere, and studies show that non-believers are more distrusted than other minorities.

Several states still ban atheists from holding public office. These rules, which are unconstitutional, are never enforced, but that hardly matters. Over 40% of Americans say they would never vote for an atheist presidential candidate.

Yet the past seven years have seen a fivefold increase in people who call themselves atheists, to 5% of the population, according to WIN-Gallup International, a network of pollsters. Meanwhile the proportion of Americans who say they are religious has fallen from 73% in 2005 to 60% in 2011.

Such a large drop in religiosity is startling, but the data on atheists are in line with other polling. A Pew survey in 2009 also found that 5% of Americans did not believe in God. But only a quarter of those called themselves atheists. The newest polling, therefore, may simply show an increase in those willing to say the word.

This change may have come about because of an informal movement of non-believers known as “New Atheism”. Over the past eight years, authors such as Richard Dawkins and the late Christopher Hitchens have attacked religion in bestselling books, appealing to logic and science. Mr Dawkins, a British biologist, has especially encouraged people to declare their disbelief.

Earlier this year he spoke at the “Reason Rally”, a gathering of thousands of secularists on the Mall in Washington, DC. “We are approaching a tipping point,” he predicted, “where the number of people who have come out becomes so great that suddenly everyone will realise, ‘I can come out too’.”

Some are doing so loudly. When Democratic convention-goers arrive in Charlotte, North Carolina, they will be greeted by a billboard sponsored by a group called American Atheists that claims Christianity “promotes hate” and exalts a “useless saviour”. A similar billboard mocking Mormonism was planned for the Republican convention, but no one would sell the group space.

American Atheists is also trying to block the display of a cross-shaped steel beam at the September 11th museum in New York. The beam, found in the wreckage of the World Trade Centre, was a totem for rescuers. The atheists see its inclusion as an unconstitutional mingling of church and state. The museum says the cross is an historical artefact, and that anyway it is not a government agency. Fights like this are unlikely to enhance atheism’s growing appeal in America.