In the case of Morrison v. Olson, 1987, the U.S. Supreme Court ruled in a 7-1 decision that the independent counsel law was constitutional under separation of powers principles and did not violate any appointments clause issues. The case arose when an independent counsel was appointed to investigate allegations against Theodore Olson, who served as an assistant attorney general for President Reagan's administration. He challenged this appointment on grounds that it violated separation of powers between executive and judicial branches because it involved judges appointing prosecutors - traditionally an executive function - and also argued that such counsels should be considered "inferior officers" requiring presidential appointment with Senate approval under Article II Section 2 Clause 2 (the Appointments Clause) of the Constitution. However, Justice Rehnquist writing for majority held that these concerns were mitigated by provisions allowing Attorney General to remove counsel for cause and maintaining ultimate prosecutorial discretion within Executive Branch.

In the dissenting opinion for Morrison v. Olson, Justice Antonin Scalia argued that the law allowing a special prosecutor to investigate high-ranking government officials was unconstitutional. He contended that it violated the separation of powers doctrine by giving too much power to a single individual who is not subject to removal or oversight by any branch of government. Scalia believed this setup could lead to abuses of power and political witch hunts, as there are no checks on the independent counsel's authority once appointed. Furthermore, he asserted that such an arrangement undermines executive privilege and disrupts balance among branches of government because it allows judicial interference in executive affairs without adequate justification or control mechanisms in place.