Christian Identity is the modern exponent of British Israelism, a theory put forth in the late 1700s. It began to take root with the publication of Our Israelitish Origins by Rev. John Wilson in the 1840s.
CI people believe that the British are the actual Israelites and that the Jews are modern-day pretenders.
It's nonsense from start to finish. There is no evidence backing up any of these ridiculous claims and they are easily disproven. However, it is a popular belief among Neo-Nazis, who are in a catch-22 because they want to believe in the Biblical tradition but also hate Jews. By redefining themselves as "the real Jews," they can do both.
For example, CI people will tell you that the first man was not Adam, but "Odom" which they say is Hebrew for "blood in the face". Since only white people can blush, this means that "Odom" was white. This kind of ridiculous thinking permeates CI publications.
A good movie on this subject is Blood in the Face, which interviews and exposes numerous CI people. Granted, Michael Moore participated in making the film (this is long before he was famous) and does some of the interviews, but really, it isn't hard to make fun of Neo-Nazis and he does it pretty well.
Christian Identity people are universally anti-Semitic and their sites, etc. often quote the Protocols of the Elders of Zion and other discredited anti-Semitic propaganda. I've never seen CI people who were not also Nazis or involved in the KKK.
WestCoastJTF
"Yet Another JTF.org Activist"