Recently Sheldon Richman has been musing about what libertarians should be concerned about.
Two essays reflect his discussion:
http://fff.org/explore-freedom/article/tgif-what-social-animals-owe-to-each-other/
http://fff.org/explore-freedom/article/tgif-in-praise-of-thick-libertarianism/
He seems to be addressing some of the issues discussed at:
http://bleedingheartlibertarians.com/
We should refrain from these efforts to complicate what it means to be a libertarian.
Both Sheldon and the Bleeding Heart Libertarians are correct in wanting people to consider moral positions that may not be derivable from the Non-Aggression Principle. But rather than attempting to expand the definition of libertarian, they should consider that ones philosophical system can have more than one principle.
Just as Euclidian geometry has more than one axiom, a philosophical system can have multiple axioms or principles. They do not all have to be derivable from one source.
No matter what we would like to be true, the way the world works is “Might makes Right”. By “right” I mean actions/possessions that people can do/keep without others interfering.
As libertarians, we are trying to gain the “might” by convincing enough people that the NAP is the best way to base how people deal with each other. That’s why I prefer referring to the NAP as the Non-Aggression Axiom. As an axiom, it does not have to be proven or justified, rather it just has to be assumed and followed.
One of the differences between libertarians and Objectivists is that that libertarians don’t care how people decide to follow the NAP – for example, whether through reason or because God said so are both okay.
I recommend that we consider as libertarians everyone who wants a governmental system based on the NAP, and derive terminology for those who who have a cluster of principles that include the NAP as a separate entity.
While one may consider, that one category is a subset of another, it is simpler to consider each principle or category as independent.