[A]lthough Article III of the US Constitution asserts that federal “judicial power shall extend to all cases, in law and equity, arising under this Constitution, the laws of the United States, and treaties made…under their authority…” it adds, “with such exceptions, and under such regulations as the Congress shall make.” Likewise, the Constitution guarantees that federal judges receive compensation for their services, which “shall not be diminished during their continuance in office,” and may serve for life during “good behaviour.” The Constitution includes no provisions specifying the size, composition, structure, or resources of the federal judiciary, leaving these matters to Congress. In fact, as Geyh (2006) points out, the Constitution puts an array of tools for controlling the federal judiciary at Congress’s disposal, including: “impeaching errant judges[,]…holding their budgets hostage, ‘unmaking’ federal courts, thwarting the appointment of ‘activist’ judges, and depriving courts of jurisdiction to hear cases on politically sensitive subjects” (p. 1; see also Ferejohn 1999).
Congressional power to curb or control federal courts was not always a museum piece. The early decades of America’s history under the Constitution offers numerous examples of Congress making use of these constitutional prerogatives to undermine or challenge the Supreme Court’s authority or independence when it ran afoul of popular majorities (e.g. Kramer 2004; Friedman 2009; Fritz 2008). Some famous examples include disbanding circuit courts (Repeal Act of 1802), postponing a Supreme Court term (Amendatory Act of 1802), impeaching a justice (Samuel Chase in 1804), manipulating the size of the Court (perhaps most cynically in the Judicial Circuits Act of 1866 and the Judiciary Act of 1869), and abrogating a Supreme Court decision with a constitutional amendment (the Eleventh Amendment superseding the Court’s holding in Chisolm v. Georgia  that Article III, Section 2 of the U.S. Constitution eliminated states’ sovereign immunity from private claims).
Indeed, the impulse to curb the Supreme Court when it acted against the preferences of popular majorities persisted well into the twentieth century. Both Presidents Roosevelt, for example, advocated ultimately unsuccessful plans to counter what they saw as excessive judicial independence. During his 1912 bid to return to the White House, Theodore Roosevelt championed a constitutional amendment that would have allowed Congress to overrule Supreme Court decisions that invalidated federal laws. In 1937, Franklin Roosevelt offered a plan that would have allowed him to appoint a new Supreme Court justice for each member of the Court over seventy years and six months old.
These episodes of muscular court curbing are mostly early deviations from a trend of greater deference to the Supreme Court by Congress and growing judicial independence and institutionalization (Kramer 2004; McGuire 2004; Segal and Spaeth 2002). Yet, they underscore a critical point: judicial authority as it exists in contemporary American politics is a fluid “political construction” rather than a firm constitutional structure (Graber 2005; see also, e.g., Clark 2009; Friedman 2009; Lovell 2003; McMahon 2004, 2011; Keck 2004; Kramer 2004; Whittington 2007; Ura and Wohlfarth 2010). In other words, independent judicial authority in the United States was established and is sustained by political processes rather than constitutional fiat.