The cultural biases in testing, combined with the subject of relationships, already guarantee discrimination. In Europe, the Rroma will be targeted; in the USA, Blacks and Hispanics. And even among Whites, liberal states will make it harder for conservative Christians and conservative states will make it harder for secularists and atheists. And everyone will make it harder for both Mormons and hippies. And that is without counting immigrant communities - Asians in the USA and Africans, Indians and Muslims in Europe.

There is no such thing as a test of mental capacity which is culturally neutral. And while that could be tolerable in a 100% homogeneos society, no contemporary society is homogeneos. Furthermore, the testers know and have always known this. And have always sneaked in mental tests as a way of excluding the undesirable from being recognized in their civil rights.

His proposal is only less brutal than literacy tests in the Jim Crow South and mental capacity tests in the North and West in that they do not involve lynching Blacks and Chinese and forcibly sterilizing Injuns and Irish.

Yes, it may prevent some victimless convictions. At the price of reviving legalized genocide disguised as eugenics.