Why Tweedledee needs Tweedledum

This is a very interesting article at RD, if only for the analysis of evangelical Christianity in America, which analysis can be summed up in these two sentences:

In sum, the threats that evangelical schools perceive have shifted somewhat over the last 100 years, but the pattern remains: evangelicalism knows what it is by fighting against what it is not.

Take its enemies away, and evangelicalism loses its identity and reason for being.

Most especially interesting because the same thing could be said of the "New Atheists" and their on-line followers.