Disqualifying the unborn’s claim to life because of some physical characteristic—such as the fetus’s primitive level of development or a congenital defect—is precisely what ethnic cleansing is about.
Ethnic cleansing is appalling for one simple reason: Valuable human beings are eradicated merely because of some physical difference or “inadequacy.” The person is condemned for his ethnicity. His features--skin, hair or eye color, shape of face, blood ancestry--are different from the accepted norm.
Abortion often kills the unborn human for the same kind of reason. The baby does not have the physical characteristics or attributes that qualify her for protection. She’s unwanted and in the way, and so she’s eliminated.
Now, if it’s wrong in the first case, it’s wrong in the second case, it seems to me. The rationale is identical. The motive is the same. In both cases the result is the death of a valuable human being.