Didn’t say he was monotone, I said his Outer Borough accent has been tamed to an extent via association with those who speak in that manner.
I have a VERY good ear for accents; especially ones from all of the 5 NYC boroughs, and can pick the sounds apart, in other's speech.
I have NEVER heard Trump's accent, before he threw in his hat, for the primary, and because it was SO strange to me, have paid a great deal of attention to it.
My grandmother was fascinated by NYC accents and I got my interest in them and learned much from her! And as I grew older, also did my own research into accents.
My accent would completely confuse you! LOL