Source of Supreme Court&#39;s authority to overrule prior Supreme Court decisions If the Supreme Court is the final authority, where does the authority of future Supreme Courts come from, to overturn prior results? Wouldn't past and future courts be of equal authority?
If the Supreme Court is the final authority The Supreme court is not the final authority. The Supreme Court is the court of last resort, but that does not prevent its case law from possibly being superseded or invalidated by constitutional amendments or the enactment of legislation. Wouldn't past and future courts be of equal authority No. Whether in the form of statutes or court decisions, laws are supposed to preserve ordered liberty. That entails the need to keep up-to-date with the state or evolution of civilization. If the Supreme Court case law --aka authorities-- were deemed inexorably perpetual, the entire judicial system would become imminently useless due to its inability to respond to new challenges [in the civilization] which are (1) encompassed by prior SC authorities, and yet (2) not properly assessed therein.
Usually, an attack on the validity or prudence of the underlying order is not a defense to court action to enforce it. Usually, the only exception would be when it was impossible, or practically impossible, to perform the court order for some reason. You could seek to modify the order, but that would be prospective in effect only and usually isn't granted unless there has been a change in circumstances since the original order was entered. You could also bring a motion to set aside judgment (usually this has to be done within six months of entry of an order) on the grounds that this provision was included only due to mistake or irregularities in the process or excusable neglect. But, that only would have only prospective effect.
While the Supreme Courts of Germany, Honduras, India and Italy have asserted such authority, the U.S. Supreme Court's justiciable decisions about a U.S. Constitutional Amendment are generally limited to a determination of whether the amendment was lawfully adopted pursuant to Article V of the U.S. Constitution, which states: The Congress, whenever two thirds of both Houses shall deem it necessary, shall propose Amendments to this Constitution, or, on the Application of the Legislatures of two thirds of the several States, shall call a Convention for proposing Amendments, which, in either Case, shall be valid to all Intents and Purposes, as Part of this Constitution, when ratified by the Legislatures of three fourths of the several States, or by Conventions in three fourths thereof, as the one or the other Mode of Ratification may be proposed by the Congress; Provided that no Amendment which may be made prior to the Year One thousand eight hundred and eight shall in any Manner affect the first and fourth Clauses in the Ninth Section of the first Article; and that no State, without its Consent, shall be deprived of its equal Suffrage in the Senate. Usually, U.S. Supreme Court litigation over a constitutional amendment would be over whether the process of Article V has been conformed to in a particular case (which has been litigated in several prior cases). The U.S. Supreme Court has held, however, in Coleman v. Miller, 307 U.S. 433 (1939), that even some procedural issues are political questions for Congress to resolve that are non-justiciable, in part because the mode of ratification is expressly delegated to Congress in Article V. As the summary of Coleman at the link above explains: In an opinion by Chief Justice Hughes, the Court held that the Kansas legislators had standing to sue, but found that two of the plaintiffs’ claims raised political questions that could only be resolved by Congress. With respect to the whether the Kansas legislature’s previous rejection of the Child Labor Amendment precluded its subsequent ratification, the Court stated that this “should be regarded as a political question pertaining to the political departments, with the ultimate authority in the Congress in the exercise of its control over the promulgation of the amendment.” But, with respect to the language in bold in the quoted language of Article V above, the U.S. Supreme Court could determine that a constitutional amendment is unconstitutional. This narrow ground, however, is the sole basis upon which it may do so.
First, the relevant term is "precedent". You have misstated the nature of "precedent". Precedent is simply the addition of further information about what the law is. A legislature may set forth a law that say "If A, then (if you B, you will suffer consequence C)". But it is not self-evident in a given instance whether A is true, or B is true, or what exactly C refers to. In addition, law is an integrated system, so Law #39 may seem to contradict Law #12: does that mean that Law #39 doesn't apply, or is it that Law #12 (if #12 is a Constitutional provision, #39 is just wrong – laws exist in a hierarchy). Therefore, laws must be interpreted. "Precedent" refers to the creation of a rule of interpretation, one which is logically consistent with existing rules of interpretation (which are arranged in some logical hierarchy). If the Supreme Court establishes a rule that laws penalizing "hate speech" contradict the First Amendment (R.A.V v. St Paul) and therefore cannot be a law in the US, then any similar law is, by rule, also not actually a law. Creation of precedent itself follows rules, though ones that are harder to discern – this is what "jurisprudence" is about. For example, some justices believe that they should appeal to an inherent feeling of justice; others believe that a law should be interpreted according to perceived legislative intent; still others focus on the wording of the legal text (statute, usually). This does not involve appeal to popular sentiment. It does mean (usually) that law is seen to be a system of rules, and not case-by-case feelings.
While it is true that jury instructions are typically less than optimal, it is ideological hyperbole or cynicism to claim that instructions are purposely confusing. The ultimate source of the confusion is that the legal system has to assume (pretend) that it has clear-cut rules that any reasonable person can easily understand and automatically apply. In order to maintain uniformity of the law, there is an externally-defined instruction that a judge may read (rather than giving his personal spin on what "reasonable doubt" means or what the relationship is between "reasonable doubt" and convicting a defendant). Once the relevant body of government (committee of judges and lawyers) has established the apparently correct formula for expressing the applicable legal concept, they don't mess with it, until SCOTUS overturns decisions enough times based on crappy instructions. Legal professionals are trained to carefully scrutinze language so as to achieve a single interpretation of a given clause (never mind the fact that there turn out to be many such interpretations). Since they can apply these interpretive rules, it is assumed that anyone can apply them. But in fact, we know that people don't just use literal semantic principles to reach conclusions – but the law resist pandering to that imperfection in human behavior. There is a huge literature on problems of jury instructions, some of the better of which relies on psycholinguistic experimentation to establish that a given instruction is confusing or gives the wrong result. See for example Solan's "Refocusing the burden of proof.." (and references therein) that addresses the problem of the "beyond a reasonable doubt" instruction, which has the unintended consequence of implying that the defense has an obligation to create a doubt (which is not the case, and allows conviction if there is the weakest imaginable evidence which hasn't been refuted). But who gets to decide what the improved instructions should say? The instructions have to correctly state what the law holds (where "the law" means not just statutes, but the trillions of relevant court decisions and applicable regulations). Thus there is massive inertia, and improved jury instructions will not come about quickly.
Prior to that act, civil procedure in federal courts was non-uniform (historical overview). The main problem seems to be that courts were supposed to conform to the procedure of the state in which the court is located (as mandated by the Conformity Act of 1872). The "has to" reason is that SCOTUS at the time did not feel that it was authorized by the Constitution to write its own rules when Congress could have done so, see Wright &amp; Miller Federal Practice and Procedure. The root problems seems to be the Process Acts of 1789 and 1792, which in the latter case did not allow courts to set rules for actions at law, and in the former case required courts to apply rules in effect when the state joined the Union (regardless of how the rules changed subsequently).
Ultimately the answer (in the US) is the US Constitution. The courts pretty much have the unlimited power to interpret the law, and the limits on power mainly pertain to what the state can do. The length of the leash on the government depends on what kind of rights are at stake. The weakest and default limit is known as "rational basis", and comes down to asking whether a government action is rationally related to a legitimate government interest (such as stopping terrorist attacks) plus whether there was due process and equal protection. There are more rigorous standards (intermediate scrutiny, strict scrutiny) in case a law involves a "suspect classification", or in case a fundamental constitutional right is infringed. In the case of strict scrutiny, the government would have to show that it had a compelling interest in the action, the law would have to be "narrowly tailored" (i.e. does that thing and only that thing), and should be the least restrictive way to achieve that result. Roe v. Wade is probably the best-know example of that kind of review, which held that abortion laws "violate the Due Process Clause of the Fourteenth Amendment, which protects against state action the right to privacy". A court would not order a party to do an impossible act. A court could order a party to do something which the party had argued was impossible, but you can interpret a court's decision to indicate that it rejected the argument. The defendant would not shoulder the burden of proving that the action was impossible, though they would have to counter the government's argument that the act could be performed if they believe it is not possible. (In the Apple case, the argument would probably be some Apple-internal document that says "Yeah, we can do it, but do we want to?"). There is probably an expense-related limit in that the courts would not order Apple to liquidate all of their assets to comply. But: if a case were to end up at the Supreme Court, the court is stricken with mass insanity and arbitrarily orders a defendant to do the impossible, there is only the option of impeachment and Senate trial to remove the offending justices, and that is just not going to happen. There is no higher authority that overturns SCOTUS.
On an issue of pure law, an appellate court decides if the trial judge got it right or wrong from scratch, and if there is a case that is a better match than the one that the judge used that leads to a different outcome in the case, then an appellate court is likely to find that the trial court's ruling is a reversible error. On an issue of mixed fact and law, or on a legal issue where a judge has more discretion in how the law is applied (like many evidentiary issues), a judge is given more deference, and the judge will generally only be reversed if no reasonable judge could have applied the correct law to the facts viewed in the light in which the judge saw them, and then, only if an application of the correct law to the facts viewed in the light in which the judge saw them would have changed the outcome of the case. There are a couple of ways that this standard of review is described, one of which is called "abuse of discretion" review.