Well, what Trump and others have difficulty understanding is the basis of American governance of individual freedom over governmental power.
Constitutionally-protected state sovereignty from the federal government is only one example of the American de-centralized power, a cornerstone of protection of individual freedom, the basis of American governance.
Study the Declaration of Independence and its central theme of God-given individual rights and freedom, the basis of self-governance. Helps to understand the presumptions of the Constitution.
States aren’t more capable, nor do they have a better track record of protecting individual freedoms. That s a myth, and a dangerous one.