Twenty-second Amendment to the United States Constitution
Some argue that the 22nd Amendment and 12th Amendment bar any two-term president from later serving as vice president as well as from succeeding to the presidency from any point in the presidential line of succession. Others contend that the original intent of the 12th Amendment concerns qualification for "service" (age, residence, and citizenship), while the 22nd Amendment, concerns qualifications for "election", and thus (strictly applying the text) a former two-term president is still eligible to "serve" as vice president (neither amendment restricts the number of times an individual can be elected to the vice presidency), and then succeed to the presidency to serve out the balance of the term (though prohibited from running for election to an additional term).
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.