Wiktionary
a. (context US English) Extremely conservative n. (context US English) A person who is extremely politically conservative; a superconservative; a radical rightwinger
Usage examples of "archconservative".
He was religious right, Christian conservative, archconservative, far right, mean-spirited, wing nut, and divisive.
In October 1960, as his soldiers were preparing to send home their absentee ballots, Walker counseled them to first consult the voting guide of the archconservative Americans for Constitutional Action.
Scaurus is going round claiming to have invented it after Saturninus began calling the archconservatives the Policy Makers.
The powerful visitor, famous as an archconservative in many ways, was quite accustomed to corruption, though there was no evidence that he ever took part.