Federal judges appointed under Article 3 of the Constitution enjoy powerful protections of their independence. They are appointed “during good behavior,” which in practice means for life (absent the vanishingly unlikely eventuality of impeachment), and they enjoy financial security against legislative or executive caprice because their salaries cannot be reduced while they remain in office.
The tenure and financial security the Constitution affords Article 3 judges are the result of the centuries-long struggle in England and America to protect judicial independence as a pillar of the rule of law.
In early medieval England, kings personally exercised virtually all the attributes of what we call “sovereignty.” They could make law alone, change the law or remit its penalties alone, and sit as judge in particular cases alone. In time, Parliament demanded a coequal share of the power to make statutory law while the power to interpret the law and to adjudicate individual cases was increasingly delegated to law-trained judges. The objective of these developments was to elevate law above the unrestrained and arbitrary will of the monarch.
Kings did not surrender their authority over law without a fight. For example, in the late 1400s, they created special so-called prerogative courts, like the infamous Court of Star Chamber, staffed primarily by the king’s councilors rather than ordinary judges, in which the rule of decision was derived from the will of the king rather than common law. When Parliament began its struggle against Stuart dynasty authoritarianism, a struggle that would lead to the English Civil War (1642–1651), the execution of King Charles I, and the creation of the English Commonwealth, one of its first acts in 1641 was to abolish the Court of Star Chamber and other prerogative courts controlled directly by the crown.
However, even after the Restoration of the monarchy under Charles II in 1660, the judges of the ordinary courts were appointed by the king and served durante bene placito regis (during the king’s pleasure). As England’s lawyers, judges, and sensible parliamentarians recognized, if the monarch could both appoint and remove judges at will, then the law could easily be bent to serve the king’s whim. Therefore, when Parliament deposed James II in the Glorious Revolution of 1688 and replaced him with King William and Queen Mary, the new monarchs were obliged to agree to the Act of Settlement. Among its other provisions, the act declared that judicial appointments would henceforth continue quamdiu se bene gesserint (during good behavior) and that even incompetent or misbehaving judges could be removed only by vote of both houses of Parliament (essentially a form of impeachment).