Is there really a sharp line between the first two groups? What those groups want to “conserve” is something that resembles the world they grew up in. Inevitably, some people who were liberal or on the left join in as the world they grew up in disappears.
“Traditional conservative” also has a meaning of its own that’s narrower than he wants to give it. It may be that there are three or four types of conservatives or rightists, but the author’s take isn’t any better than other people’s.
Yes, there is definitively a sharp line.
The dividing line is the size and scope of the federal government. Some people want dominating government issuing diktats people can’t refuse, others want to restore the U.S. Constitution to its rightful place.