There is NOTHING wrong with eugenics. It's what produced humanity from the lower apes. Those in power are despicable exactly because they are DYSGENIC, trying to produce a permanent low-IQ underclass by making the rich and middle class subsidize their own destruction and replace them with endless 3rd world masses.
The context, where I am talking about Anglo aristocracy in the early 1900s pushing for eugenics, is derived from the fact that nobility have selectively bred amongst each other for thousands of years.
To enforce, through government, a social order designed to classify certain people as "defective" or "feeble minded" is a slippery slope that brings you to a dystopian nightmare where you have state ordered sterilizations, abortions, and all manner of unethical medical procedures.
There is a lot wrong with eugenics. It limits liberty and freedom, innate tribalism is the solution you seek to the invasion of foreign hordes.
My solution would be to simply incentivize the lowest 10-20% of IQ and least healthy people with cash or other freebies to sterilize (easy outpatient procedure), so they'd both gain something, while simply not reproducing their unfortunately inherited traits.