This is historic.
No matter how things go after NH (and no matter how the Hillary hacks are going to rationalize NH), Bernie's campaign has already achieved what nobody ever thought they could. His message and his voters will be a force to be reckoned with for the future of the Democratic party. This is just the beginning.
The issue is how you expand those ideas beyond the Democratic base. This CAN be a good thing for the Democrats, but if not done right could blow up in their faces, particularly if the GOP decides not to drive themselves off a cliff.