What is the effect of the supremacy clause in the constitution?
a. states cannot pass laws that contradict the constitution.
b. the structure of government cannot change over time.
c. states can prevent the federal government from becoming tyrannical.
d. states cannot create and enforce their own laws.

A is the correct answer.

Explanation:

The supremacy clause is within the Article four of the US constitution. It dictates the federal law to be the law of the land. It means that all the judges of the states must follow the constitution, laws and treaties of the federal government. The doctrine of preemption is also based on the supremacy clause. The doctrine of preemption, preempts the state laws whenever there is a conflict in laws. The federal court can order the state courts if it thinks that its behavior is in conflict with the federal law.

slavery, abortion, donald trump, gay marriage, racial rights, immigration  

explanation:

anything that has been broth up to the supreme court is something of grate political divide   so just look as court cases