The film also points out the conflict with "family values". In conservative societies, families are supposed to love and take care of their own people who are less fortunate by birth. But that sort of feeling would run counter to the values of eugenics.
The evangelical right, to its credit, in more modern times has emphasized the value of every human life, as it fights abortion and euthanasia (sometimes, indirectly, even contraception). But the "conservatives" of the past might have favored forced abortions, as they did with sterilizations. Many states (including Virginia) had forced sterilization laws in the past.
Race has virtually nothing to do with capability for individual performance. But in general societies make different moral judgments for disability. In most of history, many cultures have viewed individual ability as connected to some idea of an absolute moral worthiness. The universe changes. Even the 1950 World Book Encyclopedia says that World War II was fought over the idea that there should exist such a thing as a master race or master nation of a particular peoples.