This week, Americans celebrate, lament, or just indifferently shrug at the fortieth anniversary of that storied 7-2 decision handed down by the Supreme Court in the case of Roe v. Wade which legalized abortion in the United States.

Aaron Blake of the Washington Post is among those shrugging his shoulders at the milestone, using the occasion to appeal to the GOP that "it's time Republicans stop talking about Roe v. Wade." It's simply a lost cause, he argues, because public opinion is continually shifting to support abortion rights. "It's hard to get 70% of Americans to agree on much of anything these days," he writes. "But, for the first time, one of those things is Roe v. Wade."

This conclusion that the trend we witness favors the pro-abortion crowd runs in stark contrast to the conclusion offered by Time magazine earlier this month. Kate Pickert offers that ever since Roe v. Wade, the pro-abortion lobby has lost significant ground in terms of both public opinion and legislation at the state level:

Even though three-quarters of Americans think abortion should be legal in some or all circumstances, just 41% identified themselves as pro-choice in a Gallup survey conducted in May 2012. In this age of prenatal ultrasounds and sophisticated neonatology, a sizable majority of Americans supports restrictions like waiting periods and parental consent laws. Pro-life activists write the legislation to set these rules. Their pro-choice counterparts, meanwhile, have opted to stick with their longtime core message that government should not interfere at all with women's healthcare decisions, a stance that seems tone-deaf to the current reality.

In other words, scientific progress lends credible evidence to the notion that a fetus within a womb represents a life. Therefore, the argument that the decision to end that life is simply matter of "choice" is becoming ever more rejected by the public.

In truth, both Blake and Pickert are right. Blake is right in concluding that revisiting Roe v. Wade is very likely a lost cause. And Pickert is right that technological advances are undermining the narrative of the pro-abortion "power brokers" who made their push for abortion rights all those years ago. But if the pretext of "choice," which was the pivotal driver leading to Roe v. Wade, is increasingly rejected by the public, why is challenging the decision such a distant possibility?

There is only one possible explanation. Because leftist engineers have constructed, and because Americans generally believe, the narrative that the decision is "settled precedent," as Justice Sotomayor puts it. And because it has been so for decades, it simply doesn't matter whether the decision and its aftermath were constitutional (they weren't), whether the principle behind it is right (it isn't), or whether the decision even makes sense anymore (it doesn't).

Rick Santorum was on to something when he confronted Al Sharpton with the logic that "abortion is acceptable for the same reason that slavery was tolerated: both the slave and the unborn are not considered full "persons" entitled to the protection of the law." The parallel is useful here.

It is pertinent to note that the right to own slaves is not explicitly protected by the Constitution. The tenderness and divisiveness of that subject at the time of our Constitution's ratification led many of our founders to regretfully leave the issue to the discretion of the states per the Tenth Amendment. Many founders, however, denounced the wickedness of the slave enterprise, noted that it was contrary to the freedoms enunciated by the Declaration, and some even anticipated that the legitimacy of slavery in the context of the Constitution would be challenged by future generations. It was, and that argument was bloody, to say the least.

Slave ownership was, however, declared constitutional by Supreme Court decree, just four years before the advent of the Civil War, handed down in Dred Scott v. Sanford. Despite the precedent having been "settled" by this Supreme Court decision in 1857, it does not change the fact that the decision was unconstitutional, morally reprehensible, and did not make any sense at all in a time when abolitionist logic arguing for slaves' humanity and freedom was becoming increasingly accepted. As such, the decision was rightfully abrogated by the Fourteenth Amendment in 1868.

Likewise, the right to abort unborn children is not specifically protected by the Constitution, and prior to 1973, abortion legislation had been understood to be limited to the power of the states per the Tenth Amendment. Roe v. Wade introduced the specious notion that that a woman's decision, however whimsical, to abort her child is protected by a "right to privacy" guaranteed by the "due process" clause of the Fourteenth Amendment. To believe that lawmakers had abortion in mind while crafting the Fourteenth Amendment requires a Herculean leap of faith. Dissenting Justice Byron White provides the more plausible reasoning:

I find nothing in the language or history of the Constitution to support the Court's judgment. The Court simply fashions and announces a new Constitutional right for pregnant women and, with scarcely any reason or authority for its action, invests that right with sufficient substance to override most existing state abortion statutes.

Roe v. Wade not only established abortion (for any chosen reason) as constitutional under curious pretenses, but it functioned as a federal edict granting new powers to the federal government -- the power to provide an eternal allowance for abortion under the newly created guidelines prescribed by the ruling. And these guidelines and timetables by which states can legally proscribe abortion (the particulars of which were clearly not included in the Fourteenth Amendment) were arbitrarily decided upon by the Court, not federal lawmakers. In spite of this seemingly egregious usurpation of the powers of the legislative branch by the judiciary, the ruling in its entirety is now somehow understood to function as law.

So under the pretense of "privacy" and "choice" and without convincing legislative grounding, wholesale abortion became allowable by federal authority. The decision only passively entertains the notion of the unborn life's humanity that is increasingly understood today, ruling that states can have some flexibility in deeming the life "viable" and protecting it in certain conditions after the first trimester -- but never before.

So yes, Roe v. Wade and its application can be convincingly described as unconstitutional. Abortion can be as morally reprehensible as murder if modern science is to be believed. And the decision's underlying principle of "choice" is being increasingly rejected by the public. But despite all of this, and despite the overwhelming support to curtail frivolous abortion at the state level in recent years, it's untouchable.

I don't necessarily argue against the conclusion that it would be a political mistake for Republicans to target Roe v. Wade. But if hindsight is truly 20/20, and in light of what we can now reasonably know to be the truth about the flaws in Roe v Wade's genesis and legacy that surpasses holocaustic magnitude, the pressing question we need to ask of our society is: Why?

William Sullivan blogs at http://politicalpalaverblog.blogspot.com/and can be followed on Twitter.