[Defend Liberty]

The 10th amendment doesn't delegate anything to the states or the people.

You better tell that to the 27 states since none of them know something you know. The 10th Amendment delegates any powers to the states not delegated to the United States and not prohibited to by it to the states. Regulating health care is not an enumerated power in Article 1 Section 8 and is not prohibited to the states or the people.

[MrB]

Perhaps the better word would be “reserves”.
The 10th reserves to the states all powers not delegated to the general gov’t.

[Huck]

You better tell that to the 27 states since none of them know something you know. They may know what I know. But they stand to benefit from the dog and pony show, whereas I don't.

The 10th Amendment delegates any powers to the states not delegated to the United States and not prohibited to by it to the states.

No, it reserves those powers. It delegates nothing.

So then the quesion becomes, what powers are those that are not delegated to the US, nor prohibited to the states, and second, under the Constitution, who decides such questions?

The answer, of course, is that the federal judiciary decides what powers are or are not delegated to the US. The states don't get to decide. You can't have some states deciding one way, and other states another way. That's not how the Constitution lays it out.

Regulating health care is not an enumerated power in Article 1 Section 8

You've never heard of implied powers? You should read up on it and disabuse yourself of this fantasy that the Constitution delegates expressed powers only. Would that it were so!