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Edward Corwin was a political scientist who served for decades as the McCormick Professor of Jurisprudence at Princeton. He is best known for his phrase about the American Constitution as an "invitation to struggle" among the branches (his reference was to foreign policy, but it applied more generally). But he was also known as a keen mind and the leading expert for decades on the meaning of the Constitution. He was close to Woodrow Wilson, and it was said that FDR strongly considered Corwin for nomination to the Supreme Court—the first nonlawyer to be so considered—but dropped the idea in part because of Corwin's lack of legal training.

Learned Hand was a judge who served on the Second Circuit Court of Appeals from 1924 until 1951, serving as chief judge for a lot of that time. No judge's opinions have been quoted more frequently or used as examples more often than those of Hand, clearly the most distinguished American judge never to have made it to the Supreme Court.

Robert Katzmann is the current chief judge of the Second Circuit. He is both a political scientist and a lawyer. His training in both fields—which encompasses hands-on experience across branches of government, including being a protégé of the late, great Daniel Patrick Moynihan—along with his judicial temperament, keen mind, and respect for the law and for politics, make him the clearest heir to both Corwin and Hand.

He will blush when he reads this, and it is true that I am his friend and have the bias of a friend (and fellow political scientist). But his stature and depth are also evident to all those who have served with him or appeared before him. I write about Katzmann because he has written a new book, called Judging Statutes, that is both a tour de force and must reading for anybody following a particularly critical case, Halbig v. Burwell, that I have written about before, and that may pose the greatest challenge yet to the full implementation and future of the Affordable Care Act.

The underlying point of Judging Statutes is that the American constitutional system requires a deep respect among the institutions of governance—which includes a respect by Congress and the courts for the key role that executive-branch officials play in their front-line role of interpreting the meaning and intent of the laws Congress passes in order to implement them; a respect by Congress for the difficulty of that executive role and for the role of the judiciary as independent arbiter; and very importantly, the respect of judges for the inherently political nature of Congress, and the difficulty and messiness involved in building coalitions and passing statutes. The latter may be distasteful and often worthy of ridicule, but it is baked into the constitutional order.

As Katzmann notes, from the beginning the framers understood that the nature of the legislative process would make statutes often unclear and murky for interpretation. Madison wrote in Federalist No. 37:

All new laws, though penned with the greatest technical skill, and passed on the fullest and most mature deliberation, are considered as more or less obscure and equivocal, until their meaning be liquidated and ascertained by a series of particular discussions and adjudications. Besides the obscurity arising from the complexity of subjects, and the imperfection of the human faculties, the medium through which the conceptions of men are conveyed to each other, adds a fresh embarrassment.

It is up to judges frequently to judge the meaning and import of statutes that are regularly subject to more than one interpretation—because laws by nature, as Madison said, are often obscure, equivocal, murky. What to do? Katzmann notes that since the 16th-century English decision known as Heydon's Case, the dominant mode has been to look at the purpose of the laws, to look carefully at what the legislature intends, to, in the words of that decision, "suppress the mischief and advance the remedy." Learned Hand wrote:

All [legislators] have done is to write down certain words which they mean to apply generally to situations of that kind. To apply these literally may either pervert what was plainly their general meaning, or leave undisposed of what there is every reason to suppose they meant to provide for. Thus it is not enough for a judge just to use a dictionary. If he should do no more, he might come out with a result which every sensible man would recognize to be quite the opposite of what was really intended; which would contradict or leave unfulfilled its plain purpose.

It is true that it is not always possible to come up with a definitive interpretation of what Congress intended. One of the most compelling parts of Katzmann's book is his account of three decisions that went to the Supreme Court from appeals courts, in one of which the judgment of Katzmann and his colleagues on the Second Circuit was overturned, that show the ways in which dutiful judges can come to opposite conclusions. But in most controversial cases, there are clear ways to look at legislative history, the words of a bill's architects or managers, and the overall body of the law to divine the plain purpose. And, as Katzmann writes, "At times it is difficult to ascertain purposes, and the search for purpose as to particular statutes, may be elusive. But to jettison the inquiry altogether, because of the difficulty in particular cases, means that judges will interpret statutes unmoored from the reality of the legislative process and what the legislators were seeking to do." To anyone who has spent time in Congress or any legislative body, who understands the fundamentals of the politics of a legislature, Hand and Katzmann are compelling.

Even so, there is another strain of interpretation that has arisen to challenge this one, closely identified with Justice Antonin Scalia. Known as textualism, it rejects the use of legislative history or the words of lawmakers about what they did and intended, showing disdain for much of the legislative process and the motives of lawmakers but also arguing that relying on messy and ambiguous legislative actions and interpretations gives judges too much discretion to achieve their own desired outcomes. In other words, Scalia argues that the text of the law speaks for itself. Katzmann judiciously, politely, and respectfully filets the case for textualism.

Most importantly, he does so by standing up for the fundamental role of the legislature in our constitutional structure. He writes that "wiping out legislative history, in the face of empirical evidence that Congress views it as essential in understanding its meaning, leaves us largely with a canon-based interpretative regime that may not only fail to reflect the reality of the legislative process, but may also undermine the constitutional understanding that Congress's statute-making should be respected as a democratic principle."

Now comes Halbig, which is based on one carelessly worded clause in the Affordable Care Act that the law's opponents say makes it clear that subsidies for insurance can only be given to those using insurance exchanges established by the states—not those established by the federal government because states refused to create their own exchanges. To accept this textual interpretation would mean the unraveling of much of the health-care law, with many millions of Americans no longer able to afford their insurance, with risk pools collapsing, and a broader chaos in the health care system. There are many other places in the ACA where it is clear that exchanges refer to all exchanges, however they were established and run. But most importantly, to imagine that the unraveling of the law and the removal of insurance from millions was what Congress intended is patently ridiculous.

But that is the conclusion that two judges on the D.C. Circuit came to. One, Thomas Griffith, had served for several years as the Senate's legal counsel, working closely with Republican senators like Orrin Hatch and Chuck Grassley who are ardent proponents of judges using legislative history and intent to judge statutes. Yet Griffith still abandoned context and opted for a cramped textual interpretation of the law.

Halbig will now be taken up by the full D.C Circuit, which will probably join the decision reached by a panel of the Fourth Circuit, saying it is abundantly clear what Congress intended—and it was to make sure as many Americans as possible got insurance, not to selectively deny it to those whose governors or state legislatures, often for ideological reasons, decided not to create their own exchanges. That may mean the Supreme Court will not hear the case. But if Halbig does get to the highest court, I hope that all nine justices, even those like Scalia who will not be swayed, will first read this fine and compelling book, and at minimum consider what steps should be taken to build a greater level of mutual respect and comity across the branches.

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