The Middle East stuff is nasty, but nobody's winning any votes with it either. Both sides appealing to their base. Trump praising Assad, which is just a basket of insanity, but his support won't care. He will have confirmed the opinion of people who don't think he really understands the region or has any coherent plan to deal with it, but they weren't going to vote for him in the first place.
At any rate, I think we've heard the big takeaway quote from the debate, and it's from Trump: “I’ll keep you in suspense.”
When asked whether he would accept a Clinton victory in November, Trump’s ultimate response was, “I’ll keep you in suspense.” I don’t mean to editorialize here, but this is perhaps the most alarming thing I’ve heard a presidential candidate say on a debate stage. In some ways, this is almost as bad — or maybe worse — than Trump coming out and saying he wouldn’t accept a loss. There are two principles at stake beyond accepting the legitimacy of the election system. The first is being honest about one’s plans and stances. The American presidency is not the latest Tana French novel — leaders can’t keep the people in suspense. The second is that presidential candidates cannot cast themselves in the role of investigating elections. Trump can’t do this, Clinton can’t do this. The only answer is that evaluating the fairness of the election is up to the commissions that are appointed to do this, not to the candidates themselves. Regardless of your policy beliefs, this is not how democracy works.