Twenty-second Amendment to the United States Constitution
The amendment prohibits any individual who has been elected president twice from being elected again. Under the amendment, an individual who fills an unexpired presidential term lasting greater than two years is also prohibited from winning election as president more than once. Scholars debate whether the amendment prohibits affected individuals from succeeding to the presidency under any circumstances or whether it only applies to presidential elections.
Dwight D. Eisenhower
The 22nd Amendment to the U.S. Constitution was ratified in 1951, and it set term limits to the presidency of two terms. Truman as the incumbent was not covered. Eisenhower became the first U.S. president constitutionally prevented from running for re-election to a third term.