Legislative power and judicial power.

• Author: Harrison, John (American law professor)

There are two possible accounts of the difference between the legislative and judicial powers granted by the Constitution and each has surprising implications. According to one, the difference is purely between two different government functions, making legal rules and applying them. If that is correct, then the legislative power can accomplish any legal result the judicial power can, but not vice versa (putting aside constitutional limits on the legislative power that do not result from its separation from judicial power). According to the other, the two powers differ because only the judicial power may operate on certain legal interests. If that is correct, the structural difference between the two powers depends on differences among the legal rules being made or applied, not the functions of government institutions. That understanding of the distinction underlay nineteenth century vested rights doctrine and underlies the Supreme Court's current doctrine that limits Congress' power to undo final judgments. Although the wholly structural understanding of the two powers may seem to make their separate vesting in independent institutions pointless, it does not, and not only because constitutional restrictions limit American legislatures' ability to create any legal rules they wish. Even a legislature with that power would be substantially constrained by an independent judiciary, because it would have to exercise its power openly, through legal rules, and not covertly, by influencing the judge's incentives.

Saint Augustine remarked that he understood time until someone asked him to explain it. (1) That legislative and judicial power are conceptually distinct may seem obvious, but explaining the difference between them is not so easy.

This Essay will argue that there are two possible theories of the difference between the legislative and judicial powers referred to by the Constitution, and that both of them have surprising implications. According to one account, the difference between the two powers is wholly structural, in that it depends entirely on the functions of government institutions. This account regards the difference between legislative and judicial power as the difference between the power to make legal rules and the power to apply them. The surprising implication is that although the powers differ in the form through which they are exercised, the legislative power can bring about any legal effect the judicial power can bring about, including the alteration of legal positions established by prior litigation. Some legal effects, however, can be achieved only by legislation. If the two powers are understood wholly structurally, the judicial power amounts to a sub-part of the legislative power.

The alternative to that conclusion is that the difference between the two powers is substantive in that the legislative power is limited in its operation with respect to some legal interests but not others. On this account, the limits of legislative power relative to judicial power are marked by legal interests that legislation may not change but that may be operated on by judicial power pursuant to preexisting rules. Some rights are vested. Those rights are identified, not by distinguishing between making and applying rules, but on other grounds. The classic nineteenth-century doctrine of vested rights was often described in terms of the distinction between legislative and judicial power, so the substantive roots of one leading account of that distinction are reasonably well known. As I will explain, the Supreme Court's current doctrine limiting Congress' power to undo final judgments is also substantive and not structural.

Of those two conclusions, perhaps the more surprising is the first, and it may seem so implausible that it cannot be correct. If legislative power can accomplish anything judicial power can, what is the point of assigning them to distinct institutions that are designed to be politically independent of one another? Even if the legislature has that much power, which legislatures subject to constitutional limitations do not, judicial independence can force legislators to exercise their authority through written law, and hence publicly and with as much clarity as is needed to constrain the courts.

This Essay begins by explaining how the power to make rules is in effect a perfect substitute for the power conclusively to apply them. It also points out that two possible constraints on legislative power that might be thought to be structural--requirements of generality and prospectivity--cannot plausibly be attributed to the legislative power granted by Article I of the Constitution. If the difference between legislative and judicial power involves only the functions of government institutions, a statute can do anything a judgment can do. The Essay then argues that understandings of the difference between the two powers that do constrain the legislature rest, not on different functions of government, but on the differences among legal interests. That was quite clear about the nineteenth-century doctrine of vested rights. Under that doctrine, courts held that some legal interests were immune from change by legislation enacted after the interest was created. (2) That doctrine was often justified as reflecting the separation of legislative and judicial power, but protected only some legal interests, interests that were identified on grounds of justice and the public good. Perhaps more surprising is that the Supreme Court's current doctrine concerning legislative interference with judgments has the same feature: It protects some interests and not others, and identifies the protected interests on grounds that do not derive from different government functions. Indeed, the distinction the Court draws closely resembles old-style vested rights doctrine. The Essay concludes by explaining how separation of powers furthers the rule of law even if the legislature has complete control over the law's content.

1. MAKING AND APPLYING LEGAL RULES

   Perhaps the most natural account of the difference between legislative and judicial power is that it is the difference between two functions of government institutions: making legal rules and authoritatively applying legal rules.

   If that is the difference, then a legislature can in effect do anything a court can do, but not vice versa. When they decide lawsuits, courts bring about two kinds of legal results. First, they conclusively resolve disputed questions of law and fact. (3) If A sues B for breach and the court concludes that B is in breach, that conclusion will bind the parties in the future. Declaratory judgments do explicitly what all merits judgments do implicitly, conclusively establishing the legal relations of the parties under the law as it stands when the judgment is issued. (4)

   Adjudication can also involve the creation of new legal rules that bind the parties. If A prevails in a suit for damages, the judgment creates a new legal obligation, into which A's preexisting claim is said to be merged. (5) Now B must pay A, and A has no other claim against B based on those facts. Injunctions similarly create new, highly specific, legal rules by imposing obligations on the party enjoined. A manifestation of this point is the crime of contempt for violating an injunction, which is distinct from the substantive law on which the injunction rests. (6)

   A government institution that can make the legal rules whatever it wants them to be can in effect perform both of those functions. If two parties have a dispute about the consequences of pre-existing legal rules for their current relationship, a lawmaking institution can provide that whatever those consequences may have been, they shall henceforth be as the institution prescribes. If A and B are in an automobile accident, an institution with that power can say that henceforth B shall have no obligation to pay A damages arising out of that accident, whatever B's obligation previously may have been. A new legal rule could also say that future relations between A and B shall be governed on the assumption that certain events had happened in the past, and thus effectively establish facts the way a court can. An institution that can make rules thus can produce the same result as a court does in a case for damages. It can also provide that B shall have an obligation to pay, again without regard to what the parties' relationship may have been. It can state rules for B's conduct that replace or go beyond the rules that existed before, and so generate the same result as an injunction.

   Anything a law-applying institution can do a law-making institution can do, but the reverse does not hold. A law-applying institution cannot announce a wholly new rule, not derived from existing law, and use it to create new obligations like a damages judgment. Application is application of the pre-existing rules. (7) If legislative and judicial power are understood as law-making and law-applying power, judicial power is a sub-part of legislative power from the standpoint of legal consequences though not of legal formalities.

   Despite the long-standing association of legislative power with generality and prospectivity, neither of those features necessarily accompanies the power to make legal rules, because legal rules can be specific and retrospective. An example of specificity in the Constitution itself is in the Twenty-Second Amendment, which provides that it "shall not apply to any person holding the office of President when this article was proposed by the Congress." (8) Congress proposes constitutional amendments at particular times, and only one person can be President at one time. Despite its extreme specificity, the proviso is a legal rule. It has legal consequences when applied to facts.

   In similar fashion, a rule can be retrospective and still be a rule; if that were not possible, the problem of retrospectivity would not arise...