Death of Mainline Churches in the US

I read a very interesting article last week over at First Things. It was entitled "The Death of Protestant America: A Political Theory of the Protestant Mainline". It basically discusses the way the mainline church over the last 40 years has steadily declined in many ways as it has become increasingly liberal. Then, I read Al Mohler's blog this morning and saw he had a summary of the article and pointed out some important things for the evangelical church. He closes his summary with these words:

"The primary injury caused by mainline Protestant decline is not social but spiritual. These denominations once fueled the great missionary movement that carried the Gospel to the ends of the earth. Now, liberal Protestantism sees conversionist missions as an embarrassment. Committed to a radical doctrinal relativism, these denominations have served as poster children for virtually every theological fad and liberal proposal imaginable. Now, many of these denominations are involved in court fights to keep churches from leaving. The stream has indeed run dry.

The "Death of Protestant America" Joseph Bottum describes must serve as a warning to Evangelicals. There can be no doubt where theological revisionism and accommodationism will lead. Why, then, would some argue that Evangelicalism should follow essentially the same path? Can they not see that the liberal Protestant river has run dry?"