Sandbillies share the same branch of the evolutionary tree as hillbillies. The sandbilly is a person that lives in the remote desert, wears rags and towels, owns an AK-47 or RPG launcher, rides a camel or donkey and wages territorial battles with other sandbillies over barren swaths of lifeless sand. They are shunned and despised by their more advanced cousins, the sand-niggers.
I saw a sandbilly defending a rock behind a dune the other day on the news.
Those shiites and sunnis are just a bunch of dirty sandbillies.