It's hard to tell, because it depends on whose ox is gored.
For example, California seems to be leading the way on animal welfare--imposing restrictions on how hogs are reared and how much space hens are provided. The state is being sued over this.
Texas is setting new restrictions on abortion, which may or may not be upheld by SCOTUS. Its being sued over that.
Obamacare originally provided for all states to expand Medicaid, but SCOTUS said that was going too far, so a bunch of states haven't done it.
I could go on and on. The point is that most, perhaps all, people who have political views want the entire US to adopt their view. Historically that's not worked. So the question becomes a discussion of means to enforce uniformity.
Can California set requirements for the ham bought into the state, How about the motor vehicles--can it set tougher standards than the national ones. Can Missouri set standards for what its women do outside of the state? Can Texas restrict what comes in the mail (ie. the morning after pills)?
Historians may remember that the Southern states were setting restrictions on anti-slavery material being mailed into the state, while officials in Northern states often resisted enforcing the Fugitive Slave Law.
Can anyone come up with a neutral standard that reasonably navigates these issues?