From a piece by Lazarowitz at Am Thinker:
With our inalienable rights to life and liberty, one might assume that among our unenumerated rights would also rest the rights of voluntary association and contract (such as the relationship between a doctor and patient) and the right to not buy insurance if one doesn't want it, as well as the right to opt out of a government health scheme. One might also assume that individuals have an inalienable, natural right to not report their medical status to the government.
The Founders were clear that such unenumerated rights would be recognized by natural law -- that is why they wrote and unanimously approved the Declaration of Independence -- but our natural rights may not be protected by constitutional law. Barnett has also wondered whether "mandatory insurance" is unconstitutional. However, given that our natural rights are inalienable, meaning that government may not take them away for any reason, it really should not matter if any of the health care proposals in Congress are unconstitutional.