R. Yehuda Henkin, Bnei Banim, vol. 4 p. 32n.:
However, according to the Sefer Ha-Chinukh (495, 496), "Do not turn to the right or the left from the words they say to you" (Deut. 17:11) applies to the great Torah scholars [Gedolim] of every generation. The Chayei Adam (127:1) wrote similarly that something established by the geniuses [ge'onim] of our times... one is biblically prohibited from deviating as it says "Do not turn." However, the source for the words of the Sefer Ha-Chinukh are not clear and the views of the Rambam and Ramban is to the contrary. See what I wrote in Bnei Banim 2:23:5. The Ritva wrote in his novellae (Mossad Ha-Rav Kook edition, Shabbos 130a) in the name of the Ra'avad that "Do not turn" applies to every rabbi in his city. While his source is also unclear, it seems to me that his intention is not like the Sefer Ha-Chinukh but that nowadays, when it is impossible to to fulfill "And you shall arise and go up to the place..." (ibid.) then "Do not turn" applies to every rabbi in his city because he is "The judge there in those days" (ibid.). It does not apply to the great scholars of a generation, putting their rule over the entire world.