Final answer:
The true statement about the powers of the national government is that its powers have expanded due to the 'necessary and proper clause'. This clause has allowed for the growth of implied powers, enabling federal involvement in extensive policy areas. Additionally, the supremacy clause ensures federal law supersedes state law in conflicts.
Step-by-step explanation:
A true statement about the powers of the national government is that the amount of power the national government has exercised has grown over the last 200 years as a result of the "necessary and proper clause". The powers that are specifically listed in the Constitution are called the expressed powers. In addition, the national government has implied powers suggested by the Constitution, which are not specifically spelled out but are inferred from the expressed powers, like the power to regulate interstate commerce which allows the government to prohibit racial discrimination on public transportation.
Furthermore, the implied powers stem from the 'necessary and proper' or elastic clause in Article I, Section 8, of the Constitution, which allows Congress to enact laws deemed necessary and proper for executing its enumerated powers. This has enabled the federal government to involve itself in policy matters such as healthcare and tax regulation. The supremacy clause in Article VI also establishes that the federal law is 'the supreme Law of the Land,' which means that in any legal conflict between state and federal law, federal law typically prevails.