attorney. Trade regulation includes antitrust law, which seeks to prevent monopolies and other restraints of trade under America's system of free enterprise. It also includes laws designed to prevent unfair competition among businesses. Labor law protects the well-being of employees and the rights and duties of labor unions. Tax law primarily concerns the federal income tax. Types of Law: Private Law Private law, often referred to as civil law, includes tort, contract, family, commercial, and property law. States are the primary source of private law. Tort law is a system of providing compensation between individuals for private wrongs, such as battery and defamation. The enforcement of promises or obligations between individuals is the subject of contract law. Family law deals with the relationships between husband and wife or parent and child: marriage and divorce; spousal abuse and support; and child custody, abuse, support, and adoption. Commercial law, derived primarily from the Uniform Commercial Code, governs the sale and lease of goods. Property law governs transactions in real estate. The Appointment of Judges The process for appointing state judges varies from state to state. Most state trial judges are elected by popular vote or by the state legislature. The supreme court judges in most states are appointed for a fixed term by the governor, and then periodically stand unopposed for reelection based on their records. In some states the judges of the highest court are elected by popular vote. State judges usually serve for a fixed term of years or for life, and can be removed only for gross misconduct by formal proceedings. Federal judges are appointed by the president with the advice and consent of the Senate. This process typically results in the appointment of judges who are members of the president's political party. If the Senate judiciary committee is controlled by the president's opposition party, the confirmation process can be hotly contested. Federal judges are appointed for life, and can be removed only by impeachment and conviction by Congress. The Role of Judges State and federal judges perform various important roles in the American legal system. Trial judges referee cases under the rules of procedure and evidence. The trial judge also instructs the jury concerning the substantive law that is applicable to the case. In bench trials, the judge determines the facts, law, and result without a jury. The role of appellate judges is to review the record of evidence before the trial court, decide the applicable substantive law, and either affirm or reverse the result below. In doing so, the appellate judge may announce principles of law for application by trial judges in future cases. Limitations on Judicial Power In Marbury v. Madison (1803), the Supreme Court said "[i]t is emphatically the province and duty of the judicial department to say what the law is." Judicial power, however, is not unlimited. The U.S. Constitution is the primary source for limitations on federal judicial power. The Constitution constrains federal courts to hear only "cases and controversies," which means actual cases rather than hypothetical situations or stale disputes. Under the political question