How does the supremacy clause of the us constitution affect the states apex?

The supremacy clause ensures that states do not abuse powers granted to them and remain united to the course of the union.
The supremacy clause states that should there be a conflict between state laws and federal laws, federal laws and interests should supersede over those of the states.
specifically, it establishes that the Constitution, federal laws made pursuant to it, and treaties made under its authority, constitute the supreme law of the land.Even state constitutions are subordinate to federal law.