Many thanks to my buddy oekosjoe for reminding us of the judicial nature of the first circuit riders in the USA! On the other hand, my sense is that the current circuit rider movement was named after the itinerant preachers (most of whom were Methodists) who made the rounds in the frontier where few settlements had resident clergy. In the 20th/21st century movement, I have heard a number of folks express distaste for the evangelical overtones of this practice. In the case of many Native American communities, the circuit riders are seen to have acted as agents of cultural imperialism, "civilizing" indigenous people by forbidding them to practice their religious traditions or speak their tribal languages. So these days, certain folks tend to avoid the term "circuit rider," using "eRider" or just "rider" instead.