I find your conclusion to be a bit strained. I think many people use pseudoscience or older debunked science to give a veneer of credibility to their biases and attempts to dehumanize others. However, this is not because it is based on science, but in spite of it.

True science is objective and should help us to understand the world and the people in it better. This allows us to make more reasoned and intelligent decisions on how to provide for the needs and well-being of a diverse population more effectively. There is nothing inherent in scientific understanding that leads to legitimizing dehumanization. Indeed, the more we know, the greater our understanding of the complexity and almost infinite variation in human beings. That very knowledge should logically create greater tolerance, not greater bigotry.

Those who use “Science“ to justify their dehumanizing attitudes and behaviors are being disingenuous. They are trying to create an aura of authority and legitimacy to something which is indefensible. Their efforts are no more valid than Trump’s lies about the 2020 election being stolen and have about the same amount of fictitious “evidence “ in support of them.

The way we get things back on track and foster a more enlightened and humanistic attitude is to educate the public better as to the actual facts and science behind them. Better understanding should lead to more tolerance and acceptance precisely because of the contributions of science. Indeed, I would posit that advances in scientific knowledge are the key to a more tolerant future.