The tension between states' power and federal power has existed since this country began. The Constitution is meant to strike a balance between the power of the states and the power of the federal government. While battles continue to be fought on this issue, they are now fought in the courts, at least, rather than on the battlefield. And I predict that they will continue to be fought, sometimes with the states prevailing and sometimes with the federal government prevailing. The fact is, though, that if you do not allow the federal government to have some authority over matters such as individual rights, you do not have a country at all, just a collection of states in proximity to one another. And history has already shown us, very well, that states are not necessarily all that interested in preserving individual rights.
This country, very quickly after its beginnings, amended the Constitution with the first ten amendments, which we refer to as the Bill of Rights. In the aftermath of the Civil War, it became apparent that the southern states were going to completely disregard the Bill of Rights, at least as it applied to African-Americans, and that they were also going to disregard as much as possible the 13th Amendment, which freed the slaves. Many laws were enacted, laws now referred to as "Jim Crow" laws, laws that made life as difficult as possible for African-Americans, not allowing them to vote, not allowing them to use any facilities that white people used, not allowing them to have fair trials, and so on, ad nauseum. In other words, Jim Crow laws prevented African-Americans from enjoying the rights guaranteed by the Constitution.
The 14th Amendment came about to solve this problem, stating that the states, not just the federal government, had to protect the rights of all people, as promised in the Constitution, and that all people were guaranteed the equal protection of the law. In decision after decision, the Supreme Court applied the 14th Amendment to stop states from depriving people of their rights under the Constitution and its amendments.
Had the southern states been willing to take care of the rights of all of their citizens, it is possible there would not have been a 14th Amendment. That is a "What if?" that is impossible to address now. But the fact remains, the federal government was forced to step in to ensure that African-Americans' rights were preserved. And they continue to have to do so to this day, for example, to guarantee integrated education and to guarantee for all the right to marry.
All of this is a long way of saying that the federal government should and must be the enforcer for the rights of all the people. When some states demonstrated that they were not going to do this, the 14th Amendment was enacted and is the law of the land. That part of the argument really should be over and done with by now. If there is no central authority, we are not a country. I don't think that people realize all the benefits that accrue from having this central authority. If we are not a country, but fifty different entities, commerce amongst the states would be incredibly inefficient and ineffective, each entity would have to have its own military, for coastal states, each would have to defend its own coast, there would be no national postal service, no interstate highways, no Social Security, no Corps of Engineers. The list of benefits that this arrangement affords us as individuals and as states is virtually endless.