It seems CNN realized a little too late that this debate was gonna actually be substantive rather than- whatever the PC term is for what the GOP debate was. Hence the dumb "last time on Game of Thrones" intro to spice things up.
I think Webb is trying to cast himself as representative of the last vestiges of moderate-conservative Southern democrats- which is a weird anachronism, because the minority vote is more important to Democrats in the south than ever, and Webb has a legacy of putting his foot squarely in his mouth on racial issues during his tenure as governor (and just seems kind of tone-deaf in general; he didn't seem to notice he was disagreeing with every candidate, including a former liberal republican, on most issues). If you ask me, he's aiming for VP, but is unlikely to get it because his (potential) strength with moderate white democrats doesn't shore up a weakness of Clinton or Sanders, and it's far from realized even if it did. In a sense, he seems like a kind of John Kasich analogue - a moderate, even oppositional figure at odds with the dominant current of his party, who may or may not be there to boost CNN's ratings amongst the ideologically uncomitted.
Sanders continues to depress me by being genuine enough to arouse my leftist passions but far too blunt to ever be generally electable; eventually, his socialist identification (admirable as it may be) is going to catch up with him. I speculate he and Clinton will orbit each other for awhile - before a fairly amicable concession when the left of the party isn't enough to keep him going any longer. He won't be veep for loads of good reasons, but he might end up with a cabinet post (state would be weird and inappropriate for his experience- labor, maybe?).
Clinton did a good job of playing the blandly competent stateswoman, which unfortunately probably isn't what she was going for (or needed). Her campaign needs pizazz, and she's wringing the "first plausible female candidate" sponge mighty dry for this early in the race. Nonetheless, I still think she has the best odds to A. win the nomination and B. smoothly overcome whichever Republican manages to crawl out of the centrifuge.