Let's be clear: walking into a church with a shotgun and 76 cartridges, and shooting people because their congregation welcomes gays and because most people in it are liberal, is terrorism by any known definition of the word. There is no essential difference between Adkisson and a suicide bomber who blows himself up in a cafe because he believes the patrons' country shouldn't exist. That equivalence does not depend on Adkisson's sanity; many terrorists may be insane to various degrees.
So how do we fight this battle in the "War on Terror"? Do we send Rush Limbaugh to Guantanamo? Do we waterboard Ann Coulter? Do we listen to phone conversations of every subscriber to the National Review? The absurdity of those propositions is not out of line with current policies. The concept of a war against terrorism has always been absurd.
Terrorists are dangerous criminals and we need to approach them as such. At the same time, we also have to work on building a society that is not conducive to breeding and fostering terrorism. That's not a war, but a quest.