I hear a lot of different arguments for and against the issue known as State Rights.
A "no one size fits all" theory is the reason I most often hear to support state rights and I can't see a flaw in that. To assume that one kind of solution - one kind of ideology - one idea only will work for everyone across the nation at the federal level, no matter what the demographic, no matter what perspective, and no matter what external factors is probably folly.
This is where state rights can be useful. With each state government able to do things their own way, we can offer a dish of multiple delights that can appease more than just one group of people. Such a method enhances freedom.
The downside of this, say those who are against state rights, is that if a state is allowed to do things their way, would they not be able to do things that have come to be considered undesirable by most people under federal rule, such as slavery and/or dissolving individual rights?
To this I would say that, normally, such things could fester, if the states were allowed to do anything they wanted. But this is where those who are against state rights fail to take into account something that does away with that concern: The federal Constitution.
If states continued to follow the Constitution and the Bill of Rights, such as they are currently required to do by law, then why would we have to worry about states conducting themselves in unsavory ways such as bringing back slavery and/or dissolving individual rights?
States can still follow the federal Constitution and still be very different from one another (and the federal government) in several ways, offering a multitude of possibilities to more than one kind of perspective and circumstance - more freedom.
This is often known as "Laboratories of Democracy". I happen to call it "Laboratories of Freedom", since the results are not always democratic, nor do they have to be democratic in order to be considered laboratories of freedom. The mere fact that they can do things their way, even if an undemocratic way, make them laboratories of freedom. (The federal government itself is not democratic).
In fact, the Constitution encourages this and has written it into law, in the 10th Amendment - The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States....