I don't have anything to say about the latest massacre except that this is the world we live in now. Boil together gun rights fanaticism, respect for the political freedom of all but the most vocal and committed revolutionaries, and our ongoing involvement in the mess that is Middle Eastern politics, and things like this are bound to happen.
And I expect them to keep happening because everybody interprets them according to previous ideological commitments. Trumps says, see, we need to keep out Muslims; liberals say, no, the problem is intolerant hate of the kind Trump foments. People for gun control say this proves we need tougher laws; people who love guns say, no, it means we need more good guys to carry weapons everywhere. Neocons are saying that we need to remove the root of the problem by destroying the Islamic State in Syria and Iraq, since its prestige convinces people around the world to swear fealty and carry out terror in its name. Those with pacifist leanings say, no, what we need is to get out the of Middle East altogether so nobody there has any reason to want to kill us; as long as our drones keep blowing up people's families, the survivors will keep attacking us.
Since no dramatic change in our policies has enough support to be carried through, we are doomed to keep going much as we have been. We will continue to combine lax gun laws with strong protections for personal liberty, such as the liberty to hang out on jihadist web sites. We will remain involved in the Middle East but we will not send a big land army to conquer the Islamic State. Various factions will continue to promote both tolerance and hate. And madmen, political or otherwise, will continue to get guns and open fire on their neighbors.