Senatorial courtesy is strictly observed in connection with federal district court judgeships, U.S. attorneys, and federal marshals. Except in rare cases, senatorial courtesy is not honored by the president or the entire Senate when the president and home state senators are of different parties.
This "courtesy" is less relied upon in the case of vacancies on the U.S. Court of Appeals. The geographic jurisdiction of these appellate courts often spans two or more states, enlarging the number of senators to be consulted and making consensus or unanimity more difficult. At times, the home state senatorial role is so strong that one senator or both senators acting together make the appointment, and the White House and the entire Senate go along with the home state senator(s).
Senatorial courtesy does not apply in the appointment of Supreme Court justices, though it did during the administration of Grover Cleveland, when political opposition of New York senator David B. Hill prevented him from gaining confirmation for a replacement to a seat traditionally held by a New Yorker. Cleveland eventually bypassed Hill by disregarding tradition and nominating a sitting senator from Louisiana.
A secondary meaning of this term refers to the deference often shown to former U.S. senators who are nominated by the president. When a president nominates a former U.S. senator to an executive branch office, the Senate often is more supportive than they would normally be. This type of "courtesy" was dealt a serious blow in 1989, when the Senate failed to confirm former U.S. senator John Tower of Texas, to be Secretary of Defense.