Not to mention that a Supreme Court ruling that health insurance is not interstate commerce would be a signed invitation for some of the Democratic trifecta states to enact state-level single payer. It probably wouldn't be a big deal on the national level if Vermont did this, but what about California or Massachusetts?
Good, that's the way it SHOULD be.
I have often wondered whether those most opposed to HCR would support the same program, or even something far to the left of it (like single payer) at the state level simply on federalist grounds. You say yes. The hope on the far left and the fear on the far right is that state level government health insurance will spread rapidly after a very influential state (like CA) adopts it. What if there was a chain reaction through the states where 35 or 40 adopted single payer over 15 years and it became the de facto national health policy, which is basically what happened to the Canadian health care system in 1945-60? Would you then regret leaving HCR completely up to the states?