States' rights is a pivotal part of our Constitution. It is something that is often ignored today as federal legislation trumps states' rights. Pushing federal legislation has been a favorite strategy of the Democrats, including the healthcare legislation recently passed.
Another key issue that landed in opposition to states' rights in abortion. State boards of medicine are given the right to determine licensure and practice rules within their borders, but the exception is abortion. What many Roe v. Wade proponents claim is that if Roe v. Wade were overturned, abortion would become illegal in the US. That's not quite true. It would in some states because laws are still on the books in some states that make it illegal. Those laws are over-riden at this time by the federal court ruling.
Several states are now challenging the healthcare legislation because they assert that it is against states' rights. It is true that states mandate all sorts of things, like car insurance (if you have a car), and they have the right to do so within their borders. But it is not within the rights of the federal government to dictate that a citizen must buy healthcare coverage.
This direction is not a good one to follow. The United States is a republic--a collection of states--and the purpose of the federal government is to protect our shared border and to regulate interstate commerce. "Regulate," as it was originally defined and intended, means "to make regular." Not "control." The idea was to get obstacles out of the way so that interstate commerce could be conducted--like provide suitable passageways (road, railways, the mail system, etc.).
The current legislature and president have taken the idea of "regulation" far beyond its intent. States have identities and cultures, and states' rights are a reflection of that. The federal government was never supposed to be "big brother" dictating what states can or cannot do. This trend does nothing but tie up the courts with challenges to state laws that states have every right to make. Instead of telling states what to do, the federal government needs to get out of the way, and let states get on with the business of managing themselves. And if you don't like some law in your state, work to change it within your state, not try to get the Supreme Court to rule it invalid.