Throughout american history, some have asserted that states (and not the supreme court) are the rightful judges of whether a law is constitutional. what would be some advantages and disadvantages of this?

If the states are the judges of whether a law is constitutional then what does the supreme court really do. I'm not saying that the citizens shouldn't have a say. It's just that is what the the supreme court does they make the final decision. Either way whether the state or the supreme court comes to a decision someone is going to make a decision. The disadvantage is that the states would be taking away the whole purpose of the supreme court. I guess I can say that a advantage is that as a person you feel as if your having some sort of say in how your state laws are being judged.

-p.s sorry is this didn't help I'm trying:(