Several Supreme Court justices and nominees, including (iirc) Antonin Scalia, have recently made obeisance to the idea of stare decisis, saying that when a constitutional decision - even if wrongly decided - has become a part of the fabric of national life or established a principle on which people rely in making significant plans, the decision should not be revisited. This is folly.
This would have made Plessy vs Ferguson the law of the land forever. More gravely, it establishes a third way (after Congressional initiation and Constitutional Conventions) to amend the Constitution. It does so because it enshrines Supreme Court opinions as perpetual statements of the meaning of the Constitution. It can even go beyond that.
Take the revisiting of the Miranda decision a few years ago. If you read Miranda, you will see that while it dealt with the Constitutional issue of application of the 5th Amendment in the context of extrajudicial confessions, the rule it established (the famous warnings) was never presented as a Constitutional mandate; it was a procedural prophylactic designed to ensure that only voluntary statements were offered in court. Recognizing that the public gains nothing from the active discouragement of cooperation with the police (society does not profit from a suspect's silence, whether he is guilty or innocent), the Congress responded to Miranda with a statute that plainly overruled it, and established a totality of circumstances test for determining the voluntariness and admissibility of statements. The statute only came before the Court decades later (because everybody followed Miranda most of the time). A statement was obtained without Miranda warnings, but with complete voluntariness. The government sought to admit the statement, relying on the statutory voluntariness test. The Supreme Court ruled the statute ineffective. It did this despite the absolute authority of the Congress to make rules of procedure and evidence (and the courts' purely interstitial authority in this regard - they can act when the Congress is silent, but cannot disregard congressional pronouncements in those areas unless the statutes conflict with the Constitution). It did this despite the fact that even the Miranda opinion makes it clear that the warnings are not constitutionally mandated. Nonetheless, because Miranda warnings have become customary, they are deemed mandatory regardless of the decisions of the Congress.
I expect that Roe vs Wade, perhaps the most nauseating exercise in jurisprudential dishonesty yet crapped out (abortion is not an issue that looms large for me; the point is that whatever you think of the policy decision, the opinion is a vile web of lies), will be upheld no matter what the Congress or any state legislature says on the matter, short of a Constitutional amendment. This will be so for the same reason that Miranda was deemed to remain law. It will be so despite the fact that the Constitution establishes no right to abortion; it will be so despite the fact that the judiciary reiterates the decision's illegitimacy every time it allows greater restrictions on rights which are explicitly protected by the Constitution than on abortion rights. 2d Amendment rights are allowed to be hedged about on all sides and even de facto eliminated at the whim of legislators, but the manufactured right to abortion is almost completely inviolate: a 17 year-old cannot buy a pistol, but a 13 year-old can have an abortion without telling her parents. If the right to abortion were actually in the Constitution, it would long since have been found subject to reasonable restrictions, as are the rights to free speech, to travel without interference, and to practice one's religion.
The recent marijuana decision is another example. Although the interstate commerce decisions of the 30s were clearly indefensible and resulted in the gutting of the Commerce Clause, turning the United States from a federal republic into a huge ill-administered municipality, a majority of the Court happily wallowed in the slop of their forebears and decided that wholly intrastate noncommercial activity is subject to federal regulation under congressional authority to govern interstate commerce.
Perhaps the worst thing about the current attachment to stare decisis is that in calling for deference even to erroneous precedent, it elevates wrong to the status of right and honors folly as though it were wisdom. The republic is still alive to a large extent, but only by chance. Given the philosophical bankruptcy of the judiciary and the power-madness of the Congress and the federal bureaucracy, there is nothing in the world to prevent the creation of a federal police force to administer a national system of laws regulating in minute detail the daily affairs of all of us; to enforce a newly discovered constitutional right of members of designated minorities to seize the property of their "oppressors." Judges - even generally good ones like Scalia - who refuse to revisit anti-Constitutional decisions simply because they are mossy with age are traitors: unwitting to be sure, but traitors nonetheless. Stare decisis, where it sanctions reverence for wrong decisions, is a great evil. It makes the way clear for the building of a totalitarian state.