At the lowest level of the federal judicial system are the district courts, where most federal cases begin. Above them are the federal courts of appeal, which review cases appealed from lower courts. The U.S. Supreme Court is the nation's highest court. Each state has its own court system, consisting of trial courts at the bottom and one or two appellate levels at the top. Cases originating in state courts ordinarily cannot be appealed to the federal courts unless a federal issue is involved, and then the federal courts can choose to rule only on the federal aspects of a case. Federal judges at all levels are nominated by the president and if confirmed by the Senate, they are appointed by the president to the office. Once on the federal bench, they serve until they die, retire or are removed by impeachment and conviction.
The Supreme Court is unquestionably the most important court in the country. Legal principles established by it are binding on lower courts and its capacity to define the law is enhanced by the control it exercises over the cases it hears. However, it is inaccurate to assume that lower courts are inconsequential (the upper-court myth). Lower courts have considerable discretion and a great majority of their decisions are not reviewed by higher courts. It is also inaccurate to assume that federal courts are far more significant than state courts (the federal court myth).
Courts have less discretionary authority than elected institutions. Judiciary positions are constrained by the facts of a case and by the laws as defined through the Constitution, statutes and government regulations, and legal precedent. Yet existing legal guidelines are seldom so precise that judges have no choice in their decisions. As a result, political influences have a strong impact on the judiciary. It responds to national conditions, public opinion, interest groups and elected officials, particularly the president and members of Congress. Another political influence on the judiciary is the personal beliefs of judges, who have individual preferences that are evident in the way they decide issues that come before them. Not surprisingly, partisan politics plays a significant role in judicial appointments.
In recent decades the Supreme Court has issued broad rulings on individual rights, some of which have required government to take positive action on behalf of minority interests. As the Court has crossed into areas traditionally left to lawmaking majorities, the legitimacy of its policies has been questioned. Advocates of judicial restraint claim that justices' personal values are inadequate justification for exceeding the proper judicial role. They argue that the Constitution entrusts broad public good issues to elective institutions and that judicial activism ultimately undermines public respect for the judiciary. Judicial activists counter that the courts were established as an independent branch and should not hesitate to promote new principles when they see a need, even if this action puts them into conflict with elected officials.