In the world of American legal scholarship, Seth Barrett Tillman is an outsider in more ways than one. An associate professor at a university in Ireland, he has put forward unusual interpretations of the meaning of the U.S. Constitution that for years have largely gone ignored — if not outright dismissed as crackpot.
But at 60, Professor Tillman is enjoying some level of vindication. When the U.S. Supreme Court considers on Thursday whether former President Donald J. Trump is barred from Colorado’s primary ballot, a seemingly counterintuitive theory that Professor Tillman has championed for more than 15 years will take center stage and could shape the presidential election.
The Constitution uses various terms to refer to government officers or offices. The conventional view is that they all share the same meaning. But by his account, each is distinct — and that, crucially for the case before the court, the particular phrase “officer of the United States” refers only to appointed positions, not the presidency.
If a majority of the court accepts Professor Tillman’s rationale, then Mr. Trump would be allowed to appear on the ballot. At issue is the meaning of Section 3 of the 14th Amendment, adopted after the Civil War, which bars people from holding office if they participated in an insurrection after having sworn to uphold the Constitution as an officer of the United States.
Professor Tillman, heavily bearded with black-rimmed glasses and a bookish demeanor, flew to the United States this week to watch the arguments. With Josh Blackman, who teaches at South Texas College of Law Houston, Professor Tillman submitted a friend-of-the-court brief and asked to participate in arguments, but the court declined.
Still, his hobbyhorse will be on the Supreme Court’s agenda, and it has drawn as much zealous backing as it has ferocious pushback.
Mr. Trump’s legal team led with the idea in its brief to the court, and many supporters of overturning Colorado’s disqualification of Mr. Trump have invoked it — including three former Republican attorneys general, Edwin R. Meese III, Michael Mukasey and William P. Barr.
But the conservative former judge J. Michael Luttig, in a withering series of posts on X, mocked Mr. Trump and his supporters for having “put all of their eggs in Blackman’s and Tillman’s tattered basket of constitutional interpretation.” He cited a recent Lawfare article that called attention to a letter Justice Antonin Scalia sent Professor Tillman in 2014 rejecting his theory. (Professors Tillman and Blackman published it in an article last year.)
During a video interview from his book-cluttered living room in Dublin, Professor Tillman gave a rueful chuckle and gestured toward his outsider status — and location — as he said that critics were objecting “in the most meanspirited and personal way, without any attempt to grapple with the ideas.”
“It’s very dispiriting,” he added. “But fortunately, I’m here. I’m in a position where I can walk away from such things.”
Akhil Reed Amar, a Yale Law School professor who submitted a brief siding with Colorado’s top court, portrayed Professor Tillman’s theory as a “gimmick” that relied on tracing words in “all these interesting little ways that makes no sense of the thing as a whole.” He predicted it would get at most three votes on the nine-member court.
At the same time, Professor Amar described Professor Tillman as a “brilliant” person who was at last gaining mainstream recognition.
“Tillman is one of the genuinely interesting people in our world, and the world hasn’t rewarded him very much,” he said. “Think about the strength of character that is required to keep plodding away for 30 years on some of these things, when no one seems to be paying any attention to you.”
Professor Tillman declined to predict how the Supreme Court would rule but said that even one vote based on his position would lend it credence as a “serious or reasonable point of view.” But asked whether he would feel vindicated if a majority of justices were to endorse it, he struck a tone of resignation.
In one sense, yes, he said. “But in the sense of would there be any vindication in the largest element of American legal academia? I think the answer is no. I think they would still say what the largest numbers have already said, which is that the particular view I put forward is wrong and if the Supreme Court adopted it, they did it for pragmatic reasons they don’t wish to acknowledge.”
The Supreme Court could also decide the case on other grounds. It could uphold the Colorado decision. Or it could restore Mr. Trump to the ballot based on different reasoning, like saying that Mr. Trump’s actions leading up to the Jan. 6, 2021, Capitol riot fell short of insurrection, or that — as Professor Tillman also argues — Section 3 would need a statute to be enforceable.
But earlier in the case, a trial judge in Denver embraced Professor Tillman’s idea. While the judge ruled that Mr. Trump’s efforts qualified as insurrection, she kept him on the ballot because, she said, presidents are not officers of the United States. The Colorado Supreme Court later disagreed. But Professor Tillman said the fact that a lower court had embraced his position already meant it could no longer be dismissed as off the wall.
An Orthodox Jew who goes offline for the Sabbath at sundown each Friday, Professor Tillman was born in New York in 1963, the second of two children. His father was a co-owner of a factory in Yonkers and his mother a homemaker.
His parents relocated to the suburbs of Rockland County when he was 7, he said, because they were alarmed that he had witnessed a murder on a playground. He said a woman had slapped a drunk man, who chased her until a janitor intervened and choked the man to death.
After earning an undergraduate degree in economics from the University of Chicago in 1984, he worked as a commodities trader and researcher until 1997, when he enrolled in Harvard Law School. Once he graduated in 2000, he bounced around for a decade, completing four judicial clerkships and a stint at two law firms — while writing academic articles on the side.
He wanted to be a law professor but had difficulty finding a full-time position. In 2011, Maynooth University School of Law and Criminology hired him as a lecturer and he moved to Ireland with his wife, now a secretary at a Dublin synagogue, and their four children. In his spare time, he said, he enjoys stargazing and East Asian history and political philosophy. This term, he is teaching equity and trusts law.
He said he was grateful for the job, but he also sounded somewhat lonely professionally. Most of his Maynooth colleagues, he noted, focus on legal questions related to Ireland or the European Union, rather than on the American constitutional issues that preoccupy him.
Professor Tillman described himself as the perpetual odd man out. His great passion, he said, has been to show that the original meaning of words and phrases in the Constitution are rooted in parliamentary understandings that quickly disappeared after its ratification, as American thinking shifted to a separation-of-powers model that emphasized the judiciary rather than Congress. Few scholars on the left or the right, he said, are interested.
“I’m not on anybody’s speed dial back in the United States — my work is very unusual,” he said, adding, “If you try to hawk that or to sell that position in the United States, within legal academia, the opportunity of finding an audience is vanishingly small.”
Professor Tillman employs a hyperclose reading of the Constitution. He assumes that the text was written with tremendous precision and intentionality, so subtle distinctions are significant — and their meaning can be inferred by carefully tracing words through the text.
His argument that presidents are not officers of the United States traces back to his response to a 1995 law journal article by Professor Amar and his brother, Vikram D. Amar, a professor at the University of California, Davis.
A law that puts the speaker of the House and the Senate president pro tem in the line of presidential succession is unconstitutional, the Amars argued, partly because of a provision that bars “holding any office under the United States” while also being a member of Congress. In a footnote, they observed that a “quibbler” might try to insist that the presidency is not an office under the United States, even as they rejected that idea.
“The whole basis of the paper, as I understood it, was that the varying terminology in the Constitution for ‘office’ and ‘officer’ all meant the same thing,” Professor Tillman recalled. “I set out on an intellectual project of saying, ‘Well, what if the Amars are wrong? What if the different “officer” phraseology in the Constitution had different meanings?’”
In short, Professor Tillman became a quibbler. As a law clerk in 2008, for example, he asserted in a paper that the winner of the 2008 presidential election, which pitted Senator Barack Obama against Senator John McCain, could keep his Senate seat while also serving as president.
Professor Tillman made various iterations of that argument, eventually catching the eye of William Baude, a University of Chicago law professor. In a short essay in 2016, Professor Baude appeared both bemused and intrigued.
“When you read an individual Tillman piece, you will notice exceedingly technical arguments combined with an almost urgent voice,” Professor Baude wrote. “You cannot help but think the author is brilliant, and you cannot help but wonder if the author is rather eccentric. As you read more of the pieces together, you will realize that he has a constitutional project, that he pursues it with great skill and knowledge, and that if he didn’t do it, nobody would.”
That did not mean Professor Baude agreed. Last summer, he co-wrote a widely cited article arguing on originalist and textualist grounds that Mr. Trump is ineligible to be president again. The essay repudiated Professor Tillman’s view, saying that phrases like “officer of the United States” must be read “sensibly, naturally and in context, without artifice” that would render it a “‘secret code’ loaded with hidden meanings.”
Professor Tillman’s theory started to get more attention as Mr. Trump’s presidency raised novel legal issues. After Mr. Trump won the 2016 election, Professor Blackman said he recognized that a president who owned a global hotel empire would lead to legal fights over the Constitution’s foreign emoluments clause. It bars people holding “any office of profit or trust under” the United States from accepting certain payments from foreign states.
Professor Blackman approached Professor Tillman and proposed they write about the office issue. In a case challenging Mr. Trump’s acceptance of foreign government patronage at the hotel he then operated in Washington, the two scholars submitted a friend-of-the-court brief arguing that the clause does not cover the presidency.
In a 2018 ruling, a federal judge in Maryland engaged at length with Professor Tillman’s view — and rejected it. That case was eventually dismissed on other grounds. But the Colorado ballot case has now given the line of inquiry even greater salience.
“His work was frantic,” Professor Blackman said. “Now everyone is listening.”
Audio produced by Jack D’Isidoro.