The Supreme Court: the Laws of the LandPart 2: Procedures of the Court
The President of the United States, by virtue of Article Two of the Constitution, can appoint Supreme Court Justices "by and with the advice and consent of the Senate." In modern times, this usually involves consultation between the President and various Senators, leading up to a formal Senate vote of confirmation, usually preceded by a couple of weeks of hearings at which the potential Justice answers questions put to him or her by members of the Senate.
Once confirmed, Justices serve "during good behavior." This usually means until the Justice dies or retires, although it can also mean the Justice leaving by being impeached. (This has never happened. One Justice Samuel Chase, in 1805 was impeached, but he was acquitted by the Senate.) As a result, many Justices serve for decades before leaving the Court.
Cases get to the Supreme Court through several different pathways. The most common is on appeal from a federal Court of Appeals. The party that lost a case in a federal Court of Appeals can petition the Supreme Court through a writ of certiorari (or "cert"). The Supreme Court does not have to accept an appeal. In fact, only a certain percentage of appeals are granted every year, mainly because the Justices physically don't have time to review all appeals and must choose the ones that are the most vital to be decided in a timely fashion.
Original jurisdiction is another way that a case can get to the Supreme Court. The Court cites original jurisdiction to resolve a dispute between two States (such as New Hampshire and Montana) or between a State and the United States.
The Supreme Court decides to hear cases from other pathways as well, but cert and original jurisdiction are the most common.
When the Court decides to hear a case, the Court issues a date for that hearing. It is then up to the lawyers representing both sides to file a "brief" with the Court. This brief contains a summary and details of the argument that the lawyers will make to support their position. The Court may also accept briefs from people who will not be directly arguing the case but who want to have their views known. This kind of brief is called amicus curiae, or "friend of the Court." On the day of the hearing, lawyers for both sides have 30 minutes to make their case in oral arguments before the Court. All members of the Court attend these hearings, and they may ask questions of the lawyers doing the arguing.
Once the oral arguments finish, the Justices agree to decide the case. A subsequent private conference includes a preliminary vote by all Justices who attended the hearing, to see who is prepared to support which side. The Court's nine members voice their preference, and out of this preliminary tally comes a Majority and a Minority. The senior Justice in the Majority assigns the writing of the eventual opinion to either himself or herself or another Justice in the Majority.
During the next several weeks, that Justice will research current law and past Court opinions in order to write the opinion that will eventually become the official pronouncement of the Court. Other Justices are free to join the official opinion or to write their own opinions. A separate opinion written by a Majority Justice is called a concurring opinion. An opinion from a member or members of the Minority is called a dissenting opinion.
Supreme Court Justices will have been appointed by Presidents who belong to one of the two major political parties. The President who appointed each Justice has the expectation that that Justice will "agree" with the thinking of the President's political party on most major issues. This does happen in many cases, although the Court is supposed to be independent and guided by "past precedent," or its previous decisions.
Much is made of the number of Justices who vote in favor or against certain arguments. Because the Court has nine members, a tally of five Justices is enough to issue a Majority opinion. Unanimous decisions are seen to carry more weight because they are viewed as being so momentous and clear-cut that all nine Justices have agreed on the particulars of the case. It is often the case, however, that the votes are "closer" than that.