When I set out to write Who Am I to Judge?, I wanted to explore a simple but powerful question: what makes a great Supreme Court justice?
Over the course of my career, from clerking for Justice Thurgood Marshall to teaching constitutional law at Harvard, Georgetown, and Wisconsin, I’ve seen how debates over judicial philosophy dominate conversations around the Court. But in my view, we’ve been asking the wrong questions.
Looking at Great Justices Without Theory
Instead of relying on my own instincts, which would inevitably reflect my own political leanings, I reviewed various existing lists of great justices compiled by others.
I settled on one published in 2003 that included ten justices who were widely respected and which struck me as relatively neutral.
What stood out immediately was that none of the justices on the list were rigid theorists. They didn’t adhere to one specific method of interpretation.
Instead, they were eclectic. They drew on whatever sources seemed helpful for solving the particular constitutional issue in front of them. Their decisions often resonated with different constitutional theories, but they were not theory driven. They were practical.
Another thing that stood out was the depth and range of their life experiences. Many of them had substantial public service careers before they ever joined the bench.
John Marshall, for example, served as a military aide to George Washington, a member of Congress, and Secretary of State before becoming Chief Justice. Earl Warren was Governor of California. These were not judges who had spent their entire careers in the judiciary.
From that analysis, I identified five common traits among these justices: longevity in age, a significant role within their political era, meaningful experience in public life (outside the judiciary), intellectual curiosity, and a noticeable absence of allegiance to any particular judicial theory.
The Pitfalls of Judicial Theory
So how did constitutional theory become such a central focus in our modern confirmation hearings and public discourse? Much of it traces back to the conservative reaction to the Warren Court. Critics accused the Court of pursuing policy under the guise of constitutional interpretation.
In response, originalism, the idea that the Constitution should be interpreted based on its original public meaning, was developed and promoted as a principled alternative. Over time, it became a core part of the Republican Party’s judicial agenda.
While critiques of originalism itself are numerous and well documented, my concern in this book is more fundamental. I question the idea that constitutional theory, in general, is what we should be asking of our judges. Theoretical frameworks can narrow judicial thinking and pull judges away from the lived realities of the people their decisions affect.
Judges with wide-ranging life experience, who have been in politics, military service, public administration, or simply held diverse roles in society, bring to the bench a sense of how law operates in the real world. That experience matters. It shapes their judgment in ways that theory cannot.
When I studied the Hughes Court, which I wrote about in a previous book, I noticed how Justice Charles Evans Hughes handled complex constitutional questions.
In one opinion, he considered whether federal government employees should be disqualified from serving on juries in the District of Columbia. He reasoned that excluding such a large group would make it nearly impossible to seat a jury. That was not a theoretical argument. It was a policy judgment rooted in practical governance.
Yes, we can retrofit some of these opinions to align with modern theories. But the judges themselves were not operating from theory. They were lawyers doing their jobs, relying on professional judgment, precedent, analogical reasoning, and a grounded understanding of law’s function in society.
What We Should Expect From Judges
When we ask what makes a good judge, I believe the answer lies in their craft. Judicial craft is difficult to define, partly because it evolves. Styles of legal writing and argumentation change over time.
But at its core, it is what my late colleague Charles Fried described as “what lawyers know.” It includes the ability to see analogies between different cases, to adapt solutions to new problems, and to think through consequences with care and nuance.
Lawyers are trained to reason by analogy, to distinguish cases, to recognize when something looks familiar but is different enough to demand a new approach.
That is the heart of judicial craft. Not allegiance to theory, but judgment built from experience, training, and a grounded sense of what justice looks like in practice.
What Judicial Craft Really Means
As a lawyer, you’re trained to think structurally. You’re taught to see how ideas relate, interact, and build toward something coherent.
That’s the essence of judicial craft. It’s about constructing arguments that genuinely hold together, not just chasing outcomes.
Carl Llewellyn once described jurisprudence as the “voice of singing reason,” and that phrase has always stayed with me. When I read a well-crafted opinion, even if I disagree with the result, I can still follow the logic.
A strong opinion has internal consistency. Every part contributes to a larger whole.
In the book, I try to capture what makes an opinion well-crafted. It should be transparent, legally grounded, familiar in form, aware of its audience, and respectful of opposing views.
You’re addressing people whose claims are being denied. But those same people remain part of the political community you serve.
There’s an old saying: “Don’t go away mad, just go away.” That mindset is the wrong one for any judge to have.
What we should convey instead is this: “I see why this matters to you. Here’s why, after careful thought, I reached a different conclusion.”
We owe people that seriousness. That explanation helps preserve community even when claims are rejected.
Why Theory Isn’t Enough
When I wrote Who Am I to Judge?, I imagined several different kinds of readers. Judges, decision-makers, and citizens curious about the courts all came to mind.
But in truth, I was writing mostly for engaged citizens. People who care about the Constitution but may not have a law degree.
I framed the book as if I were advising a president. But that was just a rhetorical move to get at something bigger.
I wanted to speak to ordinary people. Especially those who’ve been told that judicial theory is the most important thing.
Too often, we assume that a justice must fit neatly into a philosophical box. That they must be an originalist, a pragmatist, or follow some other label.
But theories don’t fully constrain judges. They still leave room for personal judgment and discretion.
Even originalism, which I discuss in depth, allows for a wide range of interpretation. Just because someone says they follow a theory doesn’t mean they’ll apply it consistently.
There are many well-formed constitutional theories out there. Each one claims to provide a principled framework.
But the choice among those theories is not itself constrained. And that’s where unpredictability creeps in.
We have no way to guarantee that someone will stay consistent over decades. People grow, learn, and change.
That’s not a flaw. It’s just part of being human.
What We Often Overlook
There’s another important point that doesn’t get enough attention. Theory doesn’t tell us anything about how well someone manages people.
If you’re on the Supreme Court, you’re managing clerks and navigating group dynamics with eight other justices. That takes a different kind of skill.
A constitutional theory won’t help with time management or team leadership. But those things are central to the job.
A justice’s name appears on opinions. But much of the drafting happens behind the scenes, often by clerks.
Younger justices tend to write more themselves. Senior justices usually delegate more and focus on the higher-level thinking.
That’s not laziness. That’s smart management and prioritization.
And over time, justices develop a voice. Clerks begin to anticipate their thinking and writing style.
When I clerked for Thurgood Marshall, I saw this dynamic firsthand. It was 50 years ago, and I was too young to fully grasp it at the time.
He wasn’t a theorist or a judicial craftsman in the strictest sense. We clerks wrote most of his opinions.
Some might take issue with that. I didn’t.
Because what Justice Marshall had was judgment. He could read a brief and see what mattered.
He wasn’t always right, of course. But he had the experience and wisdom to frame legal problems clearly.
He saw the world with uncommon depth. That came from a lifetime of wide, real-world experience.
No theory can substitute for that. And no framework can replace good judgment paired with an open mind.
Author’s Profile: Mark Tushnet