KJV-Onlyism is the belief that the King James Version is the only valid English Bible translation and some go so far as to say that any other translations actually were the work of Satan. Jack Chick and a few televangelists promoted it giving the impression that it's WAY more common than it actually is, I doubt that even 0.1% of evangelicals believe this.
If anything I tend to associate Evangelicals with the NIV, which as I'm sure you're aware has a very different translation philosophy than the KJV, RSV, and versions derived from them.
