Since Misquoting Jesus, at least, bestselling author Bart Ehrman has framed his popular-level books around his own journey from fundamentalism to agnosticism. The narrative implies that agreeing with Ehrman's arguments will lead naturally to the abandonment of one's faith. It is no wonder, then, that Ehrman is public enemy #1 for some evangelical apologists. He even gets free publicity in the form of a website, the Ehrman Project, that is dedicated to refuting him.
In his critical review of the Ehrman Project, Bob Cargill points out that "most of Ehrman’s textual arguments are essentially the well-established and long-accepted consensus views of just about every worthwhile critical biblical scholar not teaching at a Christian university, seminary, or school with the word “Evangelical” in the title," and that "the criticism of Dr. Ehrman (and the larger academy by proxy) is largely being done by a small number of vocal scholars at very conservative seminaries at the behest of a campus minister and a religion major who didn’t like their faith challenged by critical scholarship."
I confess that I have not done more than look around at the Ehrman Project, but I suspect Cargill has a point. In the field of textual criticism, at least, Ehrman is a first-rate scholar whose methods are widely accepted across the theological spectrum. I would simply like to add that--in regards to textual criticism, at least--the theological spectrum includes evangelicals.
I've had a lot of respect for Ehrman's stature as a textual critic ever since Ehrman and his Orthodox Corruption of Scripture was mentioned positively in a graduate course in textual criticism that I took at Trinity Evangelical Divinity School. I regularly require my Greek Exegesis students to read an essay by Ehrman that I regard as an excellent introduction to textual criticism. I read Misquoting Jesus when it first came out and, though I disagreed with some of his examples, I was impressed by how conventional most of the content was. The only (?) really sensational bit was the anti-Christian autobiographical spin. Far from prompting me to question my faith, however, Ehrman's anti-testimony struck me as a sad parable about the dangers of a view of Scripture so narrow and rigid that it is unable to handle the evidence about the transmission of the biblical text.
It seems to me that the best response to a scholar like Ehrman is not to attempt to marginalize or denigrate his scholarship but to counter the story by showing that the practice of textual criticism need not threaten one's faith. The scholars involved in the Evangelical Textual Criticism blog do an excellent job on this score.
Note that since the only popular level work by Ehrman that I have read is Misquoting Jesus, my comments only relate to what Ehrman has to say about textual criticism.