She thought her dissertation would lead to a PhD. Now it's informing U.S. law


Three decades ago, Rosemarie Zagarri never imagined her research on 18th-century electoral politics would become urgently relevant to the preservation of democracy in 21st-century America.

headshot of Zagarri
University Professor Rosemarie Zagarri. Photo provided

Zagarri, University Professor in the Department of History and Art History in George Mason University’s College of Humanities and Social Sciences, researched state constitutions for her dissertation at Yale University and then published “The Politics of Size: Representation in the United States, 1776-1850” in 1987.

“I examined political representation during the era of the American Revolution, with a great deal of attention to the federal Constitutional Convention, congressional apportionment, the first federal election laws, and the role of state constitutions in the federal system,” Zagarri said. “Although this scholarship is now more than 30 years old, it has not been superseded by recent work.”

The Independent State Legislature Theory, or ISLT, originated in the Supreme Court case Bush v. Gore after the disputed 2000 election, when Chief Justice Williams Rehnquist wrote a concurring opinion that formed the seed of what would become the ISLT. The theory, if implemented, would overturn centuries of precedent and would free state legislatures from oversight by state courts, potentially enabling them to pass harsh voter suppression laws and extremely gerrymandered electoral maps.

The theory might also provide political cover for state legislatures to overturn the results of presidential elections.  

Former President Trump and his adherents tried to use the independent state legislature theory to challenge the results of the 2020 election. The Supreme Court declined the arguments of ISLT in 2020. However, in their dissents, Clarence Thomas, Samuel Alito, and Neil Gorsuch all endorsed it. 

“With the efforts to overturn the 2020 election, the Brennan Center for Justice at [New York University] Law School realized it was just a matter of time before the ISLT would come before the Supreme Court,” Zagarri said. “The center asked me to write a scholarly article tracing the theory of American constitutionalism, the understanding of the role of state legislatures at the Constitutional Convention, and practices in the state governments at the time of the Founding regarding federal election laws.”

Her latest research, “The Historian’s Case Against the Independent State Legislature Theory,” will be published in March by the Boston College Law Review and is available here. It was the top article download for 2022 in the field of election law.

Zagarri was a co-author and signatory on an amicus or “friend-of the court" brief, signed by other historians of the Founding era, in the Supreme Court case of Moore v. Harper. This case involves the role of the state courts in a gerrymandering issue. The plaintiffs—in this case, officials from North Carolina—made the ISLT the center of their case. Using this theory, North Carolina officials rejected the authority of the North Carolina state supreme court to vacate what it held to be an unconstitutional redistricting scheme created by the North Carolina legislature, in violation of that state's constitution. The U.S. Supreme Court heard oral arguments on the case on Dec. 7, 2022. A decision is expected in June 2023. 

“The decision in this case will impact the state of American democracy,” Zagarri said. “Although the issues involved in this case may seem obscure to the general public, they cut to the very heart of what it means to live under a constitutional system of government, guided by the separation of powers, and subject to the division of authority between the state and federal governments.”

She added, “A ruling that supports the ISLT would mark a radical departure in American government, overturning more than 250 years of precedent in the way Americans have conducted their federal elections.”

For more on the independent state legislator theory, see this article from the Brennan Center: