Yet, Christian Fundamentalism as a named movement came into existence within 20 years of Fundamentalist LDS, which by the same measure also makes it an anachronism- correct?
And as the FLDS practice "fundamental Mormonism" a la Joseph Smith and Brigham Young, they are equally valid in calling themselves "fundamentalists"; as are Baptists and other Christian fundamentalists who "do battle royal for the Fundamentals" (Curtis Lee Laws, 1920).
I think you may have missed a key phrase in this sentence in my post: " It's anachronistic, in the sense that Joseph Smith predated Fundamentalists -
who coined the term - by half a century or more." IOW, Fundamentalist Christians - whose roots as a movement date to the 1880s or 1890s - created the term (in the 190Xs or early 191Xs). OTOH, while the FLDS evidently has roots reaching into the 191Xs, they remained within the main church until excommunicated in the late 1920s or early 1930s. The FLDS did not begin to form - or take on the name - until the early 1930s or later. Where the main issues for the Fundamentalist Movement were certain key teachings of the Bible, the main issue for the FLDS people was polygamy.
IOW, as soon as anyone scratches the surface deeper than the usage of the word, "Fundamentalist" it becomes totally clear that the Fundamentalist Movement and the FLDS polygamy movement are completely unrelated. They're even unrelated geographically, the Fundamentalist Movement having its roots in the NE US and spreading nationwide and beyond, while the FLDS has SW US roots, and hasn't spread very much (a few colonies elsewhere in the western US and one one BC, Canada).
As I said above, the FLDS have free speech, and could call themselves what they like. But calling themselves Catholic LDS would not make them related to the Catholic Church. Calling themselves Lutheran LDS would not make them related to any of the Lutheran Churches in the US. And calling themselves Fundamentalist LDS would not make them related to Fundamentalist churches.
Assuming discussions of what Fundamentalists are and believe and practice are intended to have meaning. I know, I used the
M-word ...