A more thorough explanation:

The zone of interests refers to the specific interests or concerns that a law is designed to regulate or protect. This law can be a constitutional provision or legislative statute. In order to have standing when challenging state action based on a law, the plaintiff's injury must fall under the zone of interests protected by that law.

For example, if a law is designed to protect the environment, a plaintiff who has suffered harm to their property due to environmental pollution would have standing to challenge state action that violates that law. Similarly, if a law is designed to protect consumers from fraudulent business practices, a plaintiff who has been defrauded by a business would have standing to challenge state action that violates that law.

One illustrative case is Bennett v. Spear, 520 U.S. 154 (1997). In this case, the plaintiffs were environmental groups who challenged the Bureau of Land Management's decision to allow grazing on public lands. The Supreme Court held that the plaintiffs had standing to challenge the decision because they fell within the zone of interests protected by the relevant environmental laws.

Overall, the zone of interests is an important concept in determining whether a plaintiff has standing to challenge state action based on a particular law. It ensures that only those who are directly affected by the law have the ability to challenge it in court.