No, it's not.
First, the Declsration of Independence isn't a document that the USSC is called upon to interpret. The principle you cite is valid, but it's not a matter of constitutional law.
Second, the preamble of the USC has never been cited as a source of any USSC opinion. Your emphasis on that shows you don't quite have a grasp of Constitutional law.
Last, a large part of the issue is whether a fetus is a 'person.' The problem with what you cite is that it doesn't shed light at all as to whether a fetus is legally a person. The Constitution is silent on the issue - the only thing that sheds some light is the requirement to be born in the USA to be a citizen of the USA. Born, not concieved or gestated.
The USC is silent on the issue. If you want an actviist to read it your way, that's fine - just be forthright that you want an activist judge. When you play that game, it's inevitable that your judges will be in the minority from time to time, and then you have no standing to call foul on the other side's activist judges.
Citizenship does not equal personhood. You obviously are not pro-life, so your attitude makes much more sense. So, you don't know whether it's a person or not right? So, when in doubt, kill it! If it is not a person, who can tell me at precisely what stage the unborn baby becomes a person? Do tell.
Of course, it's a person. The unborn is a unique human being that feels pain and looks like a tiny baby at 10 weeks! Abortion is killing - its stops a beating heart (try denying that!). If abortion is not killing a person - what are they killing? Tell me, WHAT IS THE DIFFERENCE BETWEEN A HUMAN BEING AND A PERSON? While you are at it, please name the creature that they are killing if not a person. A blob? A frog? You sound like a pro-choice liberal.
The USC is silent on the issue. If you want an actviist to read it your way, that's fine - just be forthright that you want an activist judge. When you play that game, it's inevitable that your judges will be in the minority from time to time, and then you have no standing to call foul on the other side's activist judges.
Wrong. The USSC said that a first trimester fetus is not a person. MAN HAS SPOKEN! So, Harry Blackmun says it is not a person - that settles it as a matter of fact, right? Wrong!