Supreme Court Justice Clarence Thomas offered this opportunity for Solicitor General John Sauer to explain how the 14th Amendment acted as a correction to questions created by the 1857 Dred Scott decision, during oral arguments on Trump’s executive order on birthright citizenship on Wednesday:

CLARENCE THOMAS, ASSOCIATE JUSTICE OF THE SUPREME COURT: General Sauer, before we get into the broader national issues, would you start with Dred Scott? Dred Scott was a case about state citizenship. It was a diversity case. And, of course, we know what Chief Justice Taney did with that. How does the Citizenship Clause respond specifically to Dred Scott and answer-change, or correct-its answer as to citizenship? The other point is the Citizenship Clause refers not just to national citizenship, but also to state citizenship. Are we to have two different definitions for those? It is one word: citizens of the United States and citizens of the state wherein they reside. So as you begin, I would like you to go back to the beginning and be more specific about the answer. And I want you to explain whether or not those two definitions are the same or related, and what state citizenship is based on. JOHN SAUER, U.S. SOLICITOR GENERAL: Thank you, Justice Thomas. I will maybe start by addressing Dred Scott. As you alluded to, Dred Scott imposed one of the worst injustices in the history of this Court, and it led to the outbreak of the Civil War. It is very clear-and this Court, in all of its early cases interpreting the 14th Amendment-that the one pervading purpose, the main object of the Citizenship Clause, was to overrule Dred Scott and establish the citizenship of freed slaves. If you look at the debate and the discussion surrounding the adoption of the Citizenship Clause, what you see is a clear understanding that the newly freed slaves and their children have a relationship of domicile here, compared to not having a relationship to any foreign power. These are people who had been here for generations and clearly have no relationship to any foreign sovereign. That reinforces our point that allegiance is what the word jurisdiction means. It does not mean regulatory jurisdiction-they are talking and thinking about it in those debates in terms of allegiance. As to your second question, if you look at the text of the clause, we believe it says: born or naturalized in the United States and subject to the jurisdiction thereof are citizens of the United States and of the state wherein they reside. There is a constitutional guarantee that applies to both national and state citizenship. The key point we make is that the word reside, if you look at Justice Story’s Commentaries, was understood to mean domicile. When they say subject to the jurisdiction, and then go on to say you are a citizen of the United States and the state in which you reside, the text of the clause itself presupposes that the citizen is domiciled in the United States. They reside there. Reside means domicile in the Constitution, and that supports our interpretation as textual evidence of our domicile-based understanding of jurisdiction.

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