Turnout is always an issue, which is why it's so interesting that young voters are coming out in droves for Bernie, and that he had massive showings at his rallies. I think this is similar to what happened in Obama's first election, but here it's different because it's in the wake of Occupy and that crowd sees him as an agent of change. I don't think Hillary will motivate people to come out and vote who normally don't (which Obama did the first time), whereas Bernie has the potential to increase voter turnout. That, I suppose, is another thing he can win through these debates, although it'll probably be a bigger issue for him should he win the nomination.
As far as foreign policy goes it's kind of crazy. On the one hand this is the area most affected directly by a President's personal views, and therefore in some sense is one of the most important areas to say something important. On the other hand I believe that most relevant data regarding foreign affairs is kept from the public, which leaves a campaigning politician in a peculiar place. Either they can admit that they're not privy to classified intelligence and can't make a clear statement of intent until they're briefed (which would be ridiculously honest but would be torn to shreds by their opponents that claim that there is no 'secret intelligence') or else they can simply make bold statements about foreign policy despite being outright ignorant about vast amounts of privileged information that they can't access. Even worse, what classified information they do have access to can't be disclosed to the public and therefore any campaign statements based solely on that must probably remain unspoken. Hillary is a bit outside of this dilemma since I think she has the insider scoop on a lot of things, which means that her obfuscations will be informed in such a way that she won't be called on them by someone who 'knows better.' For Bernie, though, this is sticky, since Hillary blatantly has had higher security clearance than him and besides which has sources of her own. He can't just make fancy claims about what to do in Syria when he knows Hillary could potentially call him on it with insider info. The best course for him is to do what he's doing, which is to outline general principles of conduct without getting too specific. He's made it pretty clear, for instance, that the "Assad must go" plan should NOT be a priority, and yet he hasn't come right out and said that that whole narrative is BS and needs to end. He's left himself the option of make more specific decisions down the road. Certainly if he were to get the Dem nomination I'm sure Obama would meet with him again and the DNC would make sure he's armed to the teeth with information to win the Presidency. Until then they're not on his side and will support Hillary's bid, and so Bernie's on his own in terms of access to intelligence.
