Parties

The U.S. legal system is based on the adversarial process, which requires parties to a legal proceeding to contend against each other. From this contest of competing interests, the issues are presented to the court and fully argued. In the end, one of the parties will obtain a favorable result.

For the adversary process to fulfill its mission of producing justice, it is vital that the issues at stake be argued by persons who have a genuine interest in them. Under the old rules of COMMON-LAW PLEADING, which used to regulate who could bring a lawsuit, only a person who actually held title to disputed property could be a party in a lawsuit concerning the property. This technicality sometimes prevented a person who had the most to gain or lose on the issue from becoming a party and presenting his or her case. This rule has now been replaced by laws requiring every action to be prosecuted by the real party in interest. This is most important when one person is managing an asset for the benefit of another. For example, administrators of a deceased person's estate can sue to protect the estate's interests without having to join the beneficiaries of the estate as parties. This modern rule sharpens the issues so that the decision in a case puts a controversy to rest for all the parties involved.

The U.S. Supreme Court has developed the standing doctrine to determine whether the litigants in a federal civil proceeding are the appropriate parties to raise the legal questions in the case. The Court has developed an elaborate body of principles defining the nature and contours of standing. In general, to have standing a party must have a personal stake in the outcome of the case. A plaintiff must have suffered some direct and substantial injury or be likely to suffer such an injury if a particular wrong is not redressed. A defendant must be the party responsible for perpetrating the alleged legal wrong.

A person has standing to challenge a law or policy on constitutional grounds if he can show that the enforcement of the law or implementation of the policy infringes on an individual constitutional right. On the other hand, in most cases a taxpayer does not have standing to challenge policies or programs he is forced to financially support.