Here is a taste of a post on the subject by Fuller Theological Seminary president and Christian philosopher Richard Mouw:
During the past two months I have spoken to a rather diverse assortment of evangelical audiences: seminary and college students, marketplace folks, conservatives in mainline denominations, global Christian leaders, and megachurch staff members. I have been surprised by the fact that in each case in the Q&A time someone asked me about what I take the “evangelical” label to mean.
Needless to say, I have been asked that question often before, but never with the frequency of my recent experiences. Nor have I seen in previous years other heads in the audience nodding at the very asking of the question. It is clear that people are asking it not simply out of curiosity. They want reassurance that the label still communicates something good about who they are, because they are worried about what the term might mean to others.
I share the concern. I spoke at Chautauqua two summers ago, and a Jewish woman came up to me after my presentation and thanked me for what I said. Then she added this: “I was surprised that I enjoyed a talk by someone who calls himself an evangelical—I always thought of evangelicals as bad people!” When I asked her what she associated with that negative impression, she made it clear that she had been convinced that all evangelicals were associated with the Religious Right.
Other writers include Peter Enns, Vincent Bacote, Corwin Smidt, John Franke, John Wilson, and Mark Sargent.
The fact that no historians were included in this conversation (so far) may say more about the state of American evangelicalism than any of the participant's remarks.