Only United States citizens may vote. 2026 results by county, from South Dakota's official results file: Yes 61.5%, No 38.5% statewide.
Statewide
Title: An Amendment to the South Dakota Constitution Clarifying that an Individual Must Be a Citizen of the United States to be Eligible to Vote. Attorney General explanation: Article VII, § 2 of the South Dakota Constitution defines who is qualified to vote in state elections. Among these qualifications are age, residency, and United States citizenship requirements. Article VII, § 2 also establishes that individuals may be disqualified from voting because of mental incompetence or a felony conviction. This constitutional amendment adds people who are not United States citizens to the list of individuals disqualified from voting, clarifying the existing requirement that only citizens may vote in state elections.
The state's unofficial totals. We don't call measures.
By county
66 counties: Yes has the most votes in 61, No has the most votes in 5. The figures for each county are from the same file and add up to the statewide totals.