Tim Sandefur’s defense of the much-maligned idea of substantive due process is elegantly simple. In the context of the Fifth Amendment’s Due Process Clause (we will get to the Fourteenth Amendment in time), the argument runs roughly as follows:
- At a minimum, the Fifth Amendment’s Due Process Clause embodies the principle of legality from Magna Carta, which declares that executive and judicial deprivations of life, liberty, or property must be authorized by valid sources of law;
- Unconstitutional legislative acts (statutes) do not function as law because they are ultra vires;
- Executive or judicial deprivations “authorized” only by unconstitutional statutes are therefore deprivations without “due process of law,” no matter what procedures are employed for those deprivations;
- The Constitution contains both implicit and explicit limitations on congressional authority to authorize valid deprivations, including an implicit general ban on arbitrary legislative action; and so
- Attempts by Congress to authorize substantively arbitrary deprivations of life, liberty, or property are attempts to authorize deprivations without due process of law, regardless of the procedures employed for those deprivations.
Every step in this argument is correct—sometimes even more correct than Sandefur lets on. The general ban on arbitrary federal legislative action, for example, which is likely to strike many readers as the most problematic aspect of his argument, is actually well grounded in the fiduciary obligations imposed on Congress by its status as a public agent who received delegated power. That obligation is textually embodied in the requirement that laws for the implementation of federal power be “necessary and proper” for executing those powers, with “proper” serving as a standard term to describe such fiduciary obligations. One of the most basic obligations of a fiduciary is to behave non-arbitrarily, so in principle Sandefur’s case for what he calls “substantive due process” against the federal government seems quite sound, at the very least in any instance in which Congress is relying on the Necessary and Proper Clause (which is most of the time). Nonetheless, I think that Sandefur is wrong to ascribe these consequences to substantive due process, or to the Due Process Clause at all.
Imagine any federal law that Sandefur thinks would fail his “substantive due process” test, such as (I presume) a hypothetical federal statute requiring interstate railroads to maintain racially segregated cars. According to Sandefur, would such a law have been constitutional if enacted on December 14, 1791—before the Bill of Rights was ratified?
I will venture to guess that his answer would be “no”—as well it should be. Sandefur packs his analysis of constitutionally legitimate federal action into the very concept of law, which gives it general application from the moment of ratification. Congress can only act through passing laws. The President has the “executive Power,” which just is (at least in most contexts) the power to execute laws. Federal courts have the “judicial Power,” which just is the power to decide cases in accordance with governing law. If the very concept of law is as value-laden as Sandefur would have it, then the original, unamended Constitution already forbade arbitrary federal action from June 21, 1788 onwards.
On December 15, 1791, when the Bill of Rights took effect, the due process clause codified and clarified this basic requirement of (procedural and substantive) legality but did not create it. Either no laws or, at most, very few laws or potential laws that were constitutional on December 14, 1791 suddenly became unconstitutional because of the Fifth Amendment. As with the vast majority of the provisions of the Bill of Rights, the Fifth Amendment’s due process clause is essentially a truism—though no less important or significant for having that status.
Can Sandefur therefore declare victory, because an unconstitutional statute by any other name (even if that name is not “violative of substantive due process”) would still be unconstitutional? In part, yes; it does not really matter for Sandefur’s purposes whether his proposed limitations on federal power come from the phrase “of law” in the Fifth Amendment or from the concept of law as embodied in the original Constitution’s grants of power to federal agents. If he is right about the general ban on arbitrary federal action—and he is more right than wrong about that—he is right without needing to make reference to the Due Process Clause at all. Sandefur is pretty much guaranteed half a loaf—or, to pick another metaphor, he is going to be able to get rid of unconstitutional federal bathwater.
The problem is with getting the other half of the loaf (or with keeping the baby). The Constitution, by empowering the various institutions of the federal government, functions as a kind of agency instrument with respect to those institutions. It is that agency relationship that imports a general requirement of non-arbitrariness into the power grants to federal actors. But the Constitution does not empower the states. It limits them in some fashions, but the states do not trace their basic legal authority to the federal Constitution. The Fifth Amendment Due Process Clause can readily be understood as a codification of one important aspect of the fiduciary limitations on federal agents. What can it mean, however, to import the same text into a provision that limits non-agent states?
This is a particularly important question, because almost every example of a violation of substantive due process raised by Sandefur involves state rather than federal action. Once one understands the Constitution as an agency instrument, the argument is very straightforward; the case for arbitrariness review of (at least most) federal legislation does not apply to state actors.
Here, the case for Sandefur-style arbitrariness review must take another form. If the Fourteenth Amendment’s Due Process Clause simply reiterates the principle of legality and requires traditional procedures for deprivations, then there is no real federal constitutional case for arbitrariness (or other “substantive”) review of state laws, unless one can ground such a requirement in some other part of the Fourteenth Amendment, such as the Privileges or Immunities Clause. As described above, a principle of legality embodied in the federal Constitution has a substantive bite against the national government that it does not have against the state governments. Accordingly, the case for “substantive due process” against the states turns on the answers to three questions: (1) Did the Fourteenth Amendment Due Process Clause have a different public meaning when enacted in 1868 than did the Fifth Amendment Due Process Clause when enacted in 1791; (2) if so, did that different meaning include a general prohibition on state arbitrariness analogous to the fiduciary obligations imposed on federal actors by the Constitution, and (3) would a different public meaning in 1868 actually determine the meaning of the Fourteenth Amendment?
I am not a Fourteenth Amendment scholar, so I defer to the superior learning and wisdom of others, including some participants in this exchange, for answers to questions (1) and (2). I offer only one observation on those questions and an observation on question (3).
First, in baseball, a tie goes to the runner. In constitutional law, a tie goes to the state and goes against the federal government. That is, state laws enter constitutional analysis with a presumption of constitutionality, while federal laws enter with a presumption of unconstitutionality. That is precisely the opposite of the allocation of burdens of proof typically employed in modern law, but it is the correct allocation. He who asserts must prove. The proponent of federal power must assert an affirmative grant of power to the relevant federal actor, while a proponent of state power has no such obligation; rather, the opponent of state power is necessarily asserting the affirmative existence of a federal constitutional limitation. Whatever the appropriate standard of proof may be for questions of constitutional meaning, the person asserting a limitation on state power must meet that standard.
Second, it is not obvious that the public meaning of an amendment at the time of its ratification determines its constitutional meaning. It might determine it, but it is not obvious. Article V of the Constitution declares that amendments are part of “this Constitution.” Does that make them subject as well to the interpretative conventions applicable to “this Constitution”—meaning the Constitution of 1788—including the interpretative convention that makes the hypothetical reasonable observer of 1788 the referent for meaning? If so, there is at least a plausible case that the original public meaning of 1788 determines the constitutional meaning even of amendments ratified in the distant future. If that is correct, and if the 1788 meaning of the Fifth Amendment’s Due Process Clause was essentially “principle of legality plus fair procedures,” then the case for substantive due process at the state level will be very hard to make.
In any event, we should all congratulate Timothy Sandefur for writing such a though-provoking article—and for walking away with at least half a loaf. That is a lot more than a forthright proponent of substantive due process probably expects in this business.
 GARY LAWSON, GEOFFREY P. MILLER, ROBERT G. NATELSON & GUY I. SEIDMAN, THE ORIGINS OF THE NECESSARY AND PROPER CLAUSE (2010); Robert G. Natelson, The Constitution and the Public Trust, 52 BUFF. L. REV. 1077 (2004).
 Gary Lawson & Guy I. Seidman, “Necessity, Propriety, and Reasonableness,” in THE ORIGINS OF THE NECESSARY AND PROPER CLAUSE, supra note 1, at 120.
 To be sure, the Constitution defines as “laws” anything that is enacted pursuant to the form for legislation set out in Article I, section 7. There is thus a prima facie argument that any legal norm enacted pursuant to Article I, section 7 is law, which taken baldly would rule out Sandefur’s version of substantive due process. It would also, however, rule out any form of constitutional review, including review pursuant to explicit and express constitutional limitations. There is an intellectually respectable case for such a position, but on balance there is a stronger case for a hierarchy among legal sources, with the Constitution standing hierarchically superior to Article I, section 7 enactments. See Gary Lawson, Rebel without a Clause: The Irrelevance of Article VI to Constitutional Supremacy, 110 MICH. L. REV. FIRST IMPRESSIONS 33 (2011).
 There are some applications of executive power that involve lawmaking rather than law execution, such as the governance of occupied territory during wartime. But they are exceptions to a general rule.
 On the largely declaratory but still important status of the Bill of Rights (and the few but significant exceptions to that status, such as federal governance of territories), see Gary Lawson, A Truism with Attitude: The Tenth Amendment in Constitutional Context, 83 NOTRE DAME L. REV. 469 (2008); Gary Lawson, The Bill of Rights As an Exclamation Point, 33 U. RICHMOND L. REV. 511 (1999).
 I am currently working on an article that explores the extent to which various federal activities are subject to the fiduciary requirement of equal treatment (or non-arbitrariness)—or in other words the proper scope of what today would be called “federal equal protection.” I am not yet convinced that such a requirement applies to all federal action. Federal governance of territories, for example, may not be subject to that norm, though it is, after December 15, 1791, subject to the Due Process Clause. But this is all for another day.
 Just to be clear: I did not so understand the Constitution until just a few years ago. I am perpetually indebted to Robert G. Natelson and Guy Seidman for opening my eyes and mind.
 Gary Lawson, Dead Document Walking, 92 B.U. L. REV. – (2012) (forthcoming); Gary Lawson, Legal Indeterminacy: Its Cause and Cure, 19 HARV. J.L. & PUB. POL’Y 411 (1996).
 Gary Lawson & Guy Seidman, Originalism As a Legal Enterprise, 23 CONST. COMMENTARY 47 (2006).