Several points here:
Several points here: --Writing simply is often harder than writing complexly. --Lincoln wrote the Gettysburg Address, not a speech writer. --Using a modern tool to measure the readability of English written in the 1700 and 1800's makes little sense. The language has evolved, and literacy is far more widespread. --I notice Trump is not on this list at all. I wonder how his rambling incoherent speeches would rate. I would guess as really difficult to read...which obviously does not mean that they reflect complex thoughts or good writing.