Subject, in this case, means subordinate. The newly-minted dual citizens (of federal and state citizenship) of 1868 and beyond are no longer "the people" that the government serves. They are the subordinates (slaves) of an authority no longer accountable to "The People", as there are technically none left post-1868.
If you think I'm exaggerating, I invite you to read SCOTUSblog sometime, and you'll eventually find someone (often a SCOTUS justice) mentioning how the first ten amendments of the bill of rights have now been "filtered" through the fourteenth, to see what stands and what doesn't. The only one yet to be filtered through the fourteenth is the third amendment (quartering troops). Thanks to DC V. Heller, the only one to escape unscathed is the second.
here's[1] a list of interesting cases directly affected by the 14th amendment.
[1] http://americanhistory.about.com/od/supremecourtcases/tp/Key...
I don't mean to pick on you personally. This is a community ailment.
The parent was talking about situations where you work in a free-ish market for a period of time, then can't work (for whatever reason) and then posits that these people will be discarded—as if that's the only option, or even, the most reasonable or likely option. It isn't.
I can't think of a single culture that fits the OPs premise and description of what happens to people that can't work. Can you?