I just came across a very nice example of a rhetorical structure I know I have seen many, many times:
Our national character feels like it’s possessed by every hellish ghost of American history: white supremacist patriarchs, gilded age swindlers, paranoid McCarthyists, Know-Nothings and Klansmen and con artists and terrorists.
(Source: Sarah Kendzior writing for The Globe and Mail.)
Notice that the usual comma-delimited list turns, after the word "McCarthyists", into an unpunctuated list separated by repeated use of the word "and". The effect (at least on me as a reader) is to create a simultaneous sense of both urgency (we are trying to get through this list as fast as possible) and exhaustion (this list is SO LONG that we can't even use commas any more).
Does this rhetorical technique have a name?
Best Answer
You are likely thinking of polysyndeton and asyndeton—probably the latter, but the former can achieve the same result in a different way. From your example, the list of which includes both comma-separated items and conjunction-separated items, I might conclude both could be applicable here.
Polysyndeton is the use of multiple conjunctions to stretch out a passage of prose to avoid coming to a full stop:
Asyndeton is the avoidance of conjunctions, "often resulting in a hurried rhythm or vehement effect":
(See Sylva Rhetoricae.)