The idea that the states should choose its own policies thereby being more responsive and reprehensible of the people’s wishes. Local representation was better representation.
If people in MA want liberal and socialist policies, let them have it. But if AL wants a capitalist economy, let them have it. That is liberty and freedom. If a citizen doesn’t like their states decisions or laws they could simply move to another state that suits them. Thus giving more free choice to the individual. Federal control foists too many unwanted laws that are unresponsive to the needs and sensibilities of differing thought and ideas. NY doesn't need to push their policies on someone in ID. Just because one or several states sees a problem with the laws governing an issue should not require other states that are dealing with the same issue satisfactorily to change their laws.When the Fed dictates and controls solutions they are likely to be unresponsive to the climate and issues of individual states with less political pull in the fed. Why should the people have taxes and laws they don’t want because the federal government wants to make a one size fits all decision. That belief is what a states rights-es beliefs .
Before civil war Virginia believed that Virginia was sovereign and joined a union freely and un-join if it was in their best interest. Their State's rights as they saw it.
After the Civil War states have be bullied by a federal government hat seeks to make not only major decision for the states, but for Individuals. This is called Tyranny.