So, let me see if I've gotten this correctly:
Jack Kerwick makes a wide-ranging claim about the behavior of 'ever growing legions of "libertarians".
Then he goes on to claim that those same "libertarians" are sympathetic to the violent black criminals who are currently committing crimes in Ferguson.
Then he gives an example of a single person, one Paul Craig Roberts, having made a rather anodyne statement about white people's views of the situation being influenced by "racism".
Hmmm... I guess that this Paul Craig Roberts guy must either constitute an ever growing horde all by his lonesome, or else he must be the (elected? appointed?) spokesman for all libertarians, everywhere. Wow, such a powerful guy that I've never heard of before.
Well, no, I don't see that Kerwick has presented any evidence whatsoever of those 'ever growing legions' that have so disgruntled him, nor do I see that Kerwick has proffered any evidence of those hordes of libertarians expressing sympathy for criminals and thugs. Rather, what I see is a foolish rant by someone who is projecting his hatred of his phony strawman onto all libertarians.
I'm well acquainted with that dishonest type of rhetoric, because it's pretty much an exact duplicate of how typical leftist idiots slander their imaginary Tea Party antagonists with phony outrage at their supposed evil acts.
Jack Kerwick, first heal thyself before you go out campaigning against your imaginary boogeymen and demons.
Good analysis.