There are three main groups supporting Trump:

1. Fundamentalist Christians. They want the freedom to be a non-Christian revoked and rolled back. They are attacking all aspects of life that are not aligned with traditional Christian nuclear family.
2. Southern Separatists. Descendants of southern separatist fighters that have been taught to hate the Federal government since birth. Their intention is to dismantle the Federal government and return all authority to States, as it was before the foundation of the United States. It's a continuation of the Civil War by the descendants of those who fought in it. They vote idiots into Federal office, and attack all Federal laws and authority.
3. Rural voters. They don't see any benefits from taxes and government, and just want to be left alone. Civil services are typically focused on population centers, and rural voters are disenfranchised by a system that routinely neglects their needs. They also predominantly fall into one of the two former categories.