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.
Supreme Court of the United States
Although Senate rules do not necessarily allow a negative vote in committee to block a nomination, prior to 2017 a nomination could be blocked by filibuster once debate had begun in the full Senate. President Lyndon B. Johnson's nomination of sitting Associate Justice Abe Fortas to succeed Earl Warren as Chief Justice in 1968 was the first successful filibuster of a Supreme Court nominee. It included both Republican and Democratic senators concerned with Fortas's ethics. President Donald Trump's nomination of Neil Gorsuch to the seat left vacant by Antonin Scalia's death was the second. Unlike the Fortas filibuster, however, only Democratic Senators voted against cloture on the Gorsuch nomination, citing his perceived conservative judicial philosophy, and the Republican majority's prior refusal to take up President Barack Obama's nomination of Merrick Garland to fill the vacancy. This led the Republican majority to change the rules and eliminate the filibuster for Supreme Court nominations.