If you really look at the issues that I am addressing, it breaks down to rights - which are protected under the Constitution and preventing corruption. Allowing states to legislate away rights is unconstitutional, so they simply should not be under the impression that this is within their purview. The States should have the economic independence to make their constituent populations as successful as possible, educate them as well as possible, determine their infrastructure and even decide what form of health care system that they want.
I think that the 2nd Amendment is problematic. It prevents sensible gun law. I don't happen to think that the federal government would ever ban guns that could even be written into the constitution. That said, attaching responsibility to gun ownership is necessary and not a violation of rights. Self-defense is a right, but it's not an unrestricted right. It shouldn't allow irresponsible gun nuts to keep 500 unsecured weapons in their shed or basement. These are weapons, not clocks or dishes. They are the targets of criminal enterprise. They shouldn't be bought, sold and traded in the private market like baseball cards. The absence of central registration and licensing makes straw purchases possible and rapid identification of criminal gun dealers difficult. Every gun sale should have to go through a licensed broker or a gun registry department that checks licenses so you can mitigate undocumented weapons transfers. People who wish to be weapons collectors should have a specific license to do so, with appropriate storage mandates and liability insurance so that if their weapons are stolen and used to kill or injure people, the victims are not left high and dry. In fact, everyone who keeps a weapon should have to carry liability insurance so that in the event that the weapon is lost, stolen or accidentally discharges, resulting in a death or injury, the victim or their family is compensated. Furthermore, that liability should be absolute, such that even if your weapon is used by you or anyone else, with intent to murder, the policy would still pay on a statutory basis.
Perhaps if gun ownership carried more of an onus for responsibility, there would be fewer guns falling into the wrong hands and regulating it centrally, sets one national standard, eliminating disparate State regulations. One less issue for governors to have to address during elections.
Similarly, issues like abortion or same-sex marriage should not be the burden of States. They involve civil rights which will always be held up to the Constitution. It's such a waste of time and energy having States creating legislation to please their constituents when what their constituents want may well be a violation of citizen's rights. The entire idea of having a nation with citizenship really implies that every citizen should enjoy the same legal rights regardless of the administrative division of the country in which they reside.
Is there really anyone who supports the idea of politicians being bought and paid for by special interests because of the lobby system. It is the singular most obvious source of corruption in government. The commercialization of elections in combination with the lobby system basically ensures that elected representatives are primarily working for their corporate benefactors, not their constituents.