Here is what you do: bring the concept or principle home. In other words does your friend or acquaintance have personal boundaries? Does he or she deem it important to protect oneself from harm or abuse or intrusions into ones personal space? Does he or she consider sexual harassment abusive? Does he leave his car unlocked or his home open to anyone, yes anyone, who may want to come in? Would she invite a red-necked family of gun toting fundamental Christians into her home to live? Or is she selective who she invites into her home? Would he welcome the most criminal drug dealers who have bathed themselves in the blood of their enemies to set up shop in his living room?
Who in their right mind would make it known that they were willing to financially support anyone, yes anyone, regardless of character, out of their own pocket? Who would open their own personal boundaries to invasion by anyone without regard to who they might be?
There are hundreds of examples one may apply that when considered on a personal or family basis make it absolutely clear we each have boundaries and borders. We want to be secure in our homes, in our possessions and in or lives. We are selective and protective. It's natural and normal (Duh! Natural law.) Ask your liberal friend if they think this sound reasoning is good for everyone on their street or in their neighborhood. If they reply affirmatively, you've got them. The principle applies to their community, to their town or city or college or classroom or work and to their state and ultimately to the country.
Of course, liberals will be contentious even with this sound reasoning. If so, simply state: Awesome! When can I move in? I am in need of $500 for rent. Can you have a check ready for me in the morning. Oh, and by the way, I have a drug dealer friend who would like to use your cell phone for a week. Or if they profess a religion or creed tell them when you move in you are going to hold meetings in their living room of a different religion.
Natural Law tells us that as individuals we have the right to protect ourselves and our families and property. It's fundamental. We extend that personal right of boundaries, of borders, clan, village, town, city. All of these have the natural right to protect themselves and to be selective as to who or what will be allowed within their boundaries. By illustrating this fundamental right in terms that "bring it home" there is hope that the most thoroughly indoctrinated liberal will concede boundaries and borders are a legitimate right and imperative.
Of course the argument will be along the lines of "we are all one" or that there are those who by no fault of their own are living in third world countries and are impoverished and living in "unjust" situations. Yes that is true. Simply bring it home one more time with another illustration: as individuals we have the natural right to invite into our homes whomever we will. However, we do not have the right to tell our neighbors who they must allow into their homes. Right? Yes, right! By extension this applies to neighborhoods and cities and states, etc. "But", they will yowl, "it is unjust. It is not fair." You can agree with them on this one. Life is not fair, and if they personally wish to help those who are living in diminished conditions that is their right, however, they have no right to force others to do so.
No doubt they will fall back into the emotion of, "It's not fair. It's unjust." This is the time to bring it back home to the individual. The individual has the right to determine his or her own life and how it is spent. True or not true? This will be the ultimate stumbling block of the liberal leftie. The issue becomes this: is an individual sovereign or is he or she property of the state and therefore has no rights other than those given or taken away by the state. Well, if this is their fall back position that is the subject of another post, is it not? But indeed this is what it all comes down to isn't it? Are we property of the state? Are we?