I've seen suggestions over the last few years that Hillary's health has been failing, that "something happened to her" while she was Secretary of State. Based on the debate I'll note that very few people sound as sharp and energetic at her age as she does. At any age, actually. And I'm saying this as someone who sincerely wishes her to fail. Her tone, style and presentation were spectacular.
I know that Jim Webb wrote a book about being Scots-Irish. The emotional difference between him and Chafee is like a cheap caricature of the Rebel/Yankee difference drawn by a Southerner who's still bitter about the Confederate defeat. Chafee's personality seemed to have been designed with the express purpose of giving the word "harmless" negative connotations.
O'Malley looked phony, sinister and inept. Bernie looked kooky. The general amount of craziness wasn't higher than during the GOP debates though. It was just directed towards different issues. I have no idea what the betting markets say, but I'd put Hillary's chances of winning the presidency at about 60% now.