The funny thing is how those most seriously obsessed with adding another face (particularly those on the Reagan/Trump right) seem to have no clue regarding Mt. Rushmore as a finite artistic creation of a moment--they almost envisage it more like a "hall of fame" that can be freely added to according to the will of leadership and some such chosen mass populace.
Though it fits the overall Trump-era programmatic view of arts and design; sort of like, "timeless principles" as an alibi for running roughshod over anything preexisting--even, theoretically, that which reflected said "principles" in the past. (That is, I wouldn't put it above a second-term-and-beyond Trump to tear down the White House on behalf of a more "beautiful" replacement, offering the alibi that the present building's basically Harry Truman-era and hence "not historic", etc)