Twelve Tribes?

Some analogies sound really interesting, but work out to be more trouble than they're worth. For example:

http://www.beliefnet.com/story/236/story_23639_1.html

Beliefnet had the interesting notion that America's political-religious groupings could be divided into twelve coherent groups, like the twelve tribes of ancient Israel. I think that's the rationale, anyway: it's not like they try a direct one-to-one analogy (The Christian Right is the Tribe of Judah, or some such.)

Unfortunately, the only thing that the process really illustrated is that twelve is not a good number to divide America's religious groups into. It turns out seeming arbitrary. Some of the divisions seem forced- what exactly is the difference between the Christian Right and the Heartland Culture Warriors? I'm presumably one or the other, but I can't tell which, and that's a bad sign for a tribe.

Likewise, the smaller groups seem to be arbitrary in their own way. Is "Muslims and Other Faiths" really a coherent group that will have things in common? Are Latinos a religious group in-and-of themselves, distinct from Catholics?

Some ideas just don't work out well. This sounded promising at first, but I'm afraid it works poorly as a political analysis.