Which clause of the U.S.Constitution has been most important in allowing the growth of
National power?

A) the commerce clause
B) the full faith and credit clause
C) the comity clause
D) the Tenth Amendment

The commerce clause of the U.S. Constitution, Article I, Section 8, Clause 3, has played a significant role in expanding the powers of the federal government. It grants Congress the power to regulate commerce among the states and with foreign nations. This has been interpreted by the courts to include not only the regulation of interstate commerce but also activities that affect or have a substantial impact on interstate commerce. This broad interpretation has allowed the federal government to regulate a wide range of economic and social activities, from environmental protection to civil rights. Therefore, the commerce clause has been the most important clause in allowing the growth of national power.