"It is an indisputable fact that any white with an IQ of 80 is in intellectually far superior to any black with an IQ of 140."Highly specific small entities like a particular individual can be measured, more or less accurately, but a vast entity like a 'race' with fluid ill-defined and hotly contested boundaries can never be.
Eugenics' problem for Modernity was that it was a science, all about fussily precise measurements which usually didn't reveal what its promotors (and people like Hitler) wanted to hear .
By contrast, Racism was pure poetry, all about vague metaphors, and so was custom made for Hitler's well-tuned rhetorical skills...
