IMHO, the real question is SHOULD we build Mt Rushmore today (should “we” have ever built it?).
Should all taxpaying USA citizens (<50%), under threat of incarceration, be forced to pay for it?
Who decides what it should look like? The folks in power at the moment?
Google “Davy Crockett, not yours to give...”
And then...
Google® Ben Franklin, "...if you can keep it."