Trevor Timm's article at commondreams.org provides the reason for phrasing the question this way - as opposed to asking whether Bernie could be nominated even if Hillary wins the popular vote. The Democratic establishment has a large say in who gets nominated. The mechanism is the large group of "super delegates."
Many people on Twitter expressed surprise that Hillary Clinton basically walked away with the same amount of total delegates as Bernie Sanders after the New Hampshire primary Tuesday night, despite the decisive 20-plus-point rout by Sanders.
It highlights the longstanding but little-discussed “superdelegate” system that could play a huge role in who wins the Democratic nomination this year. It turns out, the Democratic party decides its nominee in a massively undemocratic way – and is a ticking time bomb for the party and its voter base if Sanders keeps winning.
The Democratic party’s nomination will ultimately be decided by more than 4,700 delegates at its nominating convention in the summer. Most of those delegates are allocated based on votes in each state’s primary or caucus. However, the party also assigns what are known as “superdelegates” – 700 or so people who aren’t elected by anyone during the primary process and are free to vote any way they want at the convention. They are made up of members of Congress and members of the Democratic National Committee – which is made up of much of the establishment that Sanders is implicitly running against.
While they [super delegates] only make up about one-sixth of the total delegates, they are more than enough to swing the election either way – even if a candidate clearly wins a majority of votes and regular delegates during the primary season.
In other words, it could make the primary elections meaningless. Bernie could end up decisively winning the popular vote but still have the nomination stripped away from him at this summer’s convention.
Is that a realistic possibility? Could Bernie get burned by the Democratic party?
Sanders ... is losing the superdelegate race by a catastrophic amount. Party elites who have announced who they are supporting have almost universally broken towards Clinton’s camp. A recent unofficial count put Clinton’s advantage at a staggering 355-14. And given how Sanders falls well outside the establishment compared to Obama in 2008, it’s hard to see how he can gain a significant number to make up for Clinton’s lead – meaning it’s more likely that superdelegates would at least want to tip the scales in favor of Clinton, even if he ends up winning more primaries.
IMO that scenario - Bernie winning the popular vote but losing the nomination - would be a disaster for the Democratic party. But, as Timm says in his article, there is a long way to go in the primary season. On the immediate horizon is the next round of primaries (listed by AZBlueMeanie at Blog for Arizona).