While the current issue over how the duties of federalism are allocated to the national and state governments is the viability of government-subsidized low-cost healthcare, the true root of this conflict lies in the writing of the US constitution and the Bill of Rights.
To explain, the 10th amendment explicitly states that the federal government cannot infringe upon the rights of states with regards to powers not specifically delegated to them (this includes providing healthcare). However, the 14th amendment hints that all citizens in each and every state must be treated as equals in the eyes of the nation as a whole. Therefore, since some states can make healthcare harder to obtain than others, the national government can interfere and attempt to make healthcare more affordable for everyone.
Personally, I believe that the 14th amendment is supreme in this discussion as the right to life and health is an important civil right that should be protected by the US government. However, my main point is that many issues facing our political environment today, from healthcare to gun regulation, can easily trace their roots to the very documents that created our country. Clarifying these texts could potentially solve many problems.