From Barack Obama’s incendiary pastor, to Mitt Romney’s Mormonism, to Mike Huckabee’s southern Baptist roots, religion is the constant in America’s choosing of a president. Racism, sexism, health policy, the economy and Iraq have had their moments, but religion renews itself with every fresh controversy.

Even John McCain, relatively secure as presumed Republican candidate, has jettisoned a preacher whose endorsement became politically untenable.

Yet the most influential and enduring religious force in the country – elitist Christian fundamentalism – is mostly unsighted and rarely remarked upon, according to writer Jeff Sharlet.

Overt fundamentalists, the Bible thumping televangelist populists, are the antithesis of the secretive network he has identified and that is known variously as The Fellowship and The Family.