As James Madison wrote in Federalist 51 “If men were angels, no government would be necessary. If angels were to govern men, neither external nor internal controls on government would be necessary. In framing a government which is to be administered by men over men, the great difficulty lies in this: you must first enable the government to control the governed; and in the next place oblige it to control itself.” The scheme of separated powers in the Constitution is the primary means of limiting government and protecting liberty.
Free Enterprise Fund v. PCAOB (2010). CCJ filed a brief arguing that the Public Company Accounting Oversight Board, whose members are nominally "inferior" officers housed in the Securities and Exchange Commission, is an unconstitutional violation of the separation of powers and the inherent presidential power of removal. In a 5-4 decision, the Supreme Court agreed that the PCAOB was in fact a violation of presidential removal power.
Download the full CCJ brief here: Amicus Brief, Free Enterprise Fund v. Public Company Accounting Oversight Board and United States of America.