Some facts I find relevant:
1. Once the gametes fuse and their genetic information recombines, the new genetic code is unique to an individual (except in the statistically rare cases of the various identical twins).
2. That genetic code guides the development of a new life. An embryo/fetus is by definition alive - else why attempt to kill it?
3. That embryo/fetus, having derived from donated human DNA, is without question human.
So, in short, the embryo can be factually defined as "a living, unique human being". Irrespective of whether this living being is ensouled or can be considered a "person" it is indeed alive, unique, individual, and human. (It is at this point that an honest person must pause and wonder at the mentality which would set one group of humans' convenience and desire to escape natural consequences of their own willing actions over the basic right to live of a second group of humans).
-Moreover, in nature, there is an approximate 60% likelihood that this zygote will develop to term and be born a viable human infant.
-In the common interpretation of the Constitution, the word "man" has been explicitly clarified to mean any human being within the borders of the United States, and to whom ALL rights and protections have been explicitly extended by corrective Amendments.
-Moreover, Blackmun himself admits as much in his hazy argument IN FAVOR of abortion. Terms used in the section dealing with potential hazards of pregnancy include "CHILDbirth" and references to the expense and difficulty of CHILD care and rearing, and PARENTING. One does not worry about childbirth, child care, and parenting for any outcome save a human child. In his own "justification" for broadly defining "health risks" to the woman, he clearly admits that the matter being discussed is the deliberate termination of a human life.
There is what I see as the crux of the matter.
I do not have my Word copy of the Constitution here on this machine. However, it seems that I cannot recall any hint (or "penumbra" or "emanation") in the Constitution giving the Supreme Court the authority to either define when a human being is a person (negating the trimester nonsense) or to determine by broad classification when a homicide (the deliberate killing of a human being) is legally just or instead criminal murder. I seem to recall that that specific power is reserved SPECIFICALLY AND ENTIRELY to the popularly elected representative legislatures of the several States.
Thus, if my understanding of the relavant facts is sound, CLEARLY the USSC in rendering their decision on Roe v. Wade did wilfully usurp unto themselves those powers properly reserved to the States in clear violation of the Constitution.
Someone correct me if my understanding of the facts here is flawed. I intend to refine this line of thought to its uttermost before rejoining battle, and I truly want to be 100% correct in my understanding and logic when I do.