Julian Sanchez writes that politicians invoke religion to signal "I'm one of you" but the electorate also wants

political leaders to express deference to religious principles, even if we don't adhere to the same principles in our private lives.

He links to Toby Lester's article arguing that

the new century will probably see religion explode--in both intensity and variety...

The fact is that religion mutates with Darwinian restlessness. Take a long enough view, and all talk of "established" or "traditional" faith becomes oxymoronic: there's no reason to think that the religious movements of today are any less subject to change than were the religious movements of hundreds or even thousands of years ago. History bears this out. Early Christianity was deemed pathetic by the religious establishment....

He cites Rodney Stark's book Acts of Faith:

For nearly three centuries," he writes, "social scientists and assorted Western intellectuals have been promising the end of religion. Each generation has been confident that within another few decades, or possibly a bit longer, humans will 'outgrow' belief in the supernatural. This proposition soon came to be known as the secularization thesis.

And Colin Campbell:

it could be that the very processes of secularization which have been responsible for the 'cutting back' of the established form of religion have actually allowed 'hardier varieties' to flourish.

And Rodney Stark, on successful religious movements:

...success is really about relationships and not about faith. What happens is that people form relationships and only then come to embrace a religion. It doesn't happen the other way around.... You can never find that sort of thing out after the fact—because after the fact people do think it's about faith. And they're not lying, by the way. They're just projecting backwards.

Stark is also known for the rational-choice theory of religion:

People act rationally in choosing their religion. If they are believers, they make a constant cost-benefit analysis, consciously or unconsciously, about what form of religion to practice. Religious beliefs and practices make up the product that is on sale in the market, and current and potential followers are the consumers. In a free-market religious economy there is a healthy abundance of choice (religious pluralism), which leads naturally to vigorous competition and efficient supply (new and old religious movements). The more competition there is, the higher the level of consumption. This would explain the often remarked paradox that the United States is one of the most religious countries in the world but also one of the strongest enforcers of a separation between Church and State.

It looks like the Economist was reading Stark. And actually I saw it earlier, but didn't pay much attention to it.