Eugenics was practiced in the USA until the 1970s, I believe.
The famous Supreme Court case was "Buck vs Bell", in 1927. The case revolved around an 18 year-old named Carrie Buck, a patient at a Virginia state mental hospital. According to the superintendent of the facility, Carrie Buck had a mental age of 9, and her mother had a mental age of 8. Carrie had given birth to an illegitimate child who was also declared "feeble-minded." The facility recommended that she be sterilized. Her guardian filed an appeal - the case eventually went to the Supreme Court.
In an 8-1 decision, the Court ruled against Buck and supported her sterilization. It was ruled that Buck was "feeble-minded" and "promiscuous." It was in the public interest to eliminate the weak from the gene pool for future generations. The famous line from the majority statement was "Three generations of imbeciles are enough."
That decision legitimized existing sterilization laws and encouraged many states to add such laws as well. It was popularly supported and, contrary to what the OP suggests, many of the surgeries were carried out in the open, under government oversight. It was all perfectly legal and it wasn't until the 1960s case Skinner v Oklahoma that the practice began to diminish.
But here's the problem. Going back to the case of Carrie Buck: there exists the question whether or not Carrie Buck was truly "feeble-minded." Recent examinations have thrown significant doubt on the question.
When Buck was a child, her mother had been committed to a mental hospital on grounds of immorality, prostitution, and having syphilis. She was placed with a foster family, who, for whatever reason, discontinued her education after sixth grade. She was placed in a mental hospital by her foster family on the grounds of feeblemindedness, incorrigible behavior, and promiscuity. This was justified by the evidence that she'd become pregnant with an illegitimate child.
However, the likely real reason is that their nephew had raped Buck several months earlier and left her pregnant.
Carrie Buck was released after her sterilization and subsequent interviews with her revealed a woman of normal intelligence. Her child died early in life, but was a decent student. Her sister, who had also been sterilized without her knowledge, also proved to be fairly normal.
Would this stand up to modern reasoning? Would you institutionalize a woman because she was immoral, a prostitute, or had syphilis? Would you institutionalize her daughter because she was incorrigible or promiscuous? Did either deserve institutionalization when one had been raped and the other likely just an impoverished woman? And knowing that, does this create a family history justifying forced sterilization?
I understand that the OP doesn't mean this. I understand that the OP is expressly avoiding the "feeble-minded" argument that justified the sterilization of so many who were poor, sick, or foreign. I get that the OP is stressing race and ethnicity is not a factor to avoid echoing the Nazis who so strongly supported eugenics (and in fact, cited Buck vs Bell, in their speeches, their research, and later, in their defense at the Nuremberg trials).
But I bring up Buck vs Bell to prove a point - that at one point in very recent history, modern democratic states with constitutional, codified legal systems, led by intelligent, learned leaders and majorities, decided that promiscuity, incorrigibility, and pregnancy were grounds enough to institutionalize and sterilize a destitute mother and a raped teenager.
And then I ask you why we aren't capable of making similar grievous errors in judgment.
Certainly, mistakes were made. Certainly, they didn't know some things about genetics that we know now. But are we incapable of making similar mistakes? Are we truly so knowledgeable about genetics? So many diseases, we don't even know what their cause may be. We think it might be inherited, but what if it can also be environmental? What if it's recessive and it might not be passed along? What if it's a mutation that occurs without inheritance? What if it's only activated by certain environmental factors?
And where do we draw the line? What if it's a genetic defect that's easily corrected? What if it's a disease than can be treated? What if they decide all people who are cancer-risks should be sterilized? What about congenital heart disease? Diabetes? Anemia? Hemophilia? Astigmatism? Color-blindness? Male-pattern baldness?
Will you be that quick to subject yourself to the knife?
What if you're merely a carrier? You have a recessive gene which has a 50% chance of being carried on in your chromosomes and 25% chance of manifesting in your child, if you meet someone else who is also a carrier. Should you be sterilized?
And this is all very simplified genetics. The fact is, your genes are not individual switches. You activate one gene, you'll activate and deactivate others. And disease are often multiple genes in a certain alignment. Will they pass on in that format? Or will they not?
We know so very little about genetics and even less about genetic inheritance. We don't know why, for example, a genetic disease sometimes manifests in one identical twin and not the other. We don't know why some genetic diseases seem to manifest spontaneously. We don't even know what the majority of our DNA even does and what activates or deactivates them.
And the final question: is it even morally right to force sterilization? Isn't forced sterilization a violation of a basic human right - the right to procreate? Is this a violation of due process? Is this akin to killing a child because of a genetic defect? Are we administering a punishment before a crime has occurred? And is this essentially criminalizing the act of bearing a child with genetic defects?
