Final answer:
The cornerstones of the U.S. government's domestic regulatory power through the commerce clause involve Congress's ability to regulate interstate commerce, but its powers are not unlimited. Supreme Court decisions over time have shifted the breadth of this power, sometimes expanding it and other times constraining it, with an underlying balance between federal authority and states' rights.
Step-by-step explanation:
The cornerstones of the U.S. government domestic regulatory powers through the commerce clause lie in Congress's ability to regulate commerce with foreign nations, among the several states, and with Indian Tribes, as detailed in Article I, Section 8 of the Constitution. Although Congress has broad powers under this clause to regulate various aspects of the economy, its powers are not without limits. Since the 19th century, the Supreme Court consistently broadened Congress's power to regulate commerce, which notably increased during the 1930s in response to the Great Depression; however, in rulings such as United States v. E.C. Knight and United States v. Lopez, the Court has set some boundaries, emphasizing that certain regulatory powers belong to the states and confirming the need for a balance between federal and state powers.
Historically, the interpretation of the commerce clause has evolved from a narrow view, in which the government's regulatory authority was limited strictly to commercial activities and interstate business activities, to a more expansive view that includes intrastate economic transactions that have a substantial effect on interstate commerce. Nevertheless, recent developments suggest a trend toward a more restrained approach, particularly evident in the Supreme Court's decision regarding the Affordable Care Act, which was upheld based on Congress's power to tax rather than the commerce clause.