Final answer:
Changes to federal regulatory oversight of environmental protection since 2000 have largely been due to Agency rulemaking and Executive action. The EPA writes command-and-control regulations with various exemptions due to political compromises, while Presidents have also influenced policy through various executive actions.
Step-by-step explanation:
Since 2000, most changes to federal regulatory oversight of environmental protection have been due to Agency rulemaking and Executive action. The Environmental Protection Agency (EPA) is responsible for writing command-and-control regulations, which are a form of environmental protection measures that dictate specific limits and standards for pollution emissions and resource use. These regulations are a product of the political process and are subject to lobbying and compromise, leading to exemptions and loopholes. At the same time, executive actions by the President can influence environmental policy through directives, orders, and the enforcement of existing laws.
The legislative framework established by the Clean Air Act and the Clean Water Act, among other environmental laws, has seen numerous updates via the EPA's rulemaking, as influenced by changing political climates, scientific advances, and economic considerations.