D. G. Hart's Deconstructing Evangelicalism: Conservative Protestantism in the Age of Billy Graham makes the point that the term "evangelicalism" is essentially meaningless. Those who coined the term were intending to create a broad coalition of conservative Christians to function as a countervailing force to the liberal mainline denominations. In so doing, they reduced the baseline for calling oneself an evangelical to so little that the term and the movement says virtually nothing about a theological commitment to anything.
What the term did was provide a useful tool for historians and pollsters. In the past 30 years a body of literature on evangelicals and evangelicalism has exploded. Hart argues that the reason is that publishers are more likely to buy a book that can be sold to a broader market than analysis of just one distinct denomination. Folks like Gallup and Barna love evangelicalism because it likewise makes their data more interesting to more people. Of course, Hart argues that this is hardly surprising since the questions and characteristics pollsters have used to identify and track evangelicals has far more to do with social conservative politics than with theology that is faithful to the gospel.
I intend to follow this post with a couple more on some specific issues Hart addresses. This book probably is not a must-read for all evangelicals or fundamentalists since it is fairly technical and demands some prerequisite knowledge, but his conclusions ought to be discussed more than they seem to have been to this point. If you are committed to understanding the history of evangelicalism, you will not want to miss Hart's analysis.