According to
theguardian

A string of polls over the past two weeks show that the once-independent Vermont senator is tied or in the lead in the two early primary states, Iowa and New Hampshire, and all of a sudden, in striking distance of Hillary Clinton nationally.

(My bolding)
...

Digging deeper into the numbers shows even more good news for Sanders: nationally, he is beating Clinton by 2-1 with voters younger than 45, and by 20 points with female voters younger than 35. In New Hampshire there is not one demographic group in which Clinton is beating Sanders. He's also made recent gains among African Americans and Hispanics - both demographics long considered Clinton strongholds.

These are key demographics and he's winning them over by sticking to the issues that matter to them, things that actually have a big impact on their lives and our lives, and ignoring the bullshit distractions of ISIS and Syria, and 9/11, 9/11, 9/11. These are voters and he's going great guns there ... BUT

He's not doing so good with the Superdelegates. These are mostly establishment Dems, the old guard, and they're not too crazy about Bernie. Right now, HRC has a 45-1 advantage over Bernie with these people. npr.org BUT, check out the details:

November 2015 Survey

Clinton: 359
Sanders: 8
O'Malley: 2
Uncommitted: 210
Not surveyed: 133

So, who the hell are they and what can we do?
The 712 superdelegates per wikipedia are

[20] Distinguished Party Leaders (current and former Presidents, Vice-Presidents, Congressional leaders, and DNC Chairs)
[20] Democratic governors (including territorial governors and the Mayor of the District of Columbia)
[47] Democratic members of the United States Senate (including Washington, DC Shadow Senators)
[193] Democratic members of the United States House of Representatives (including non-voting Delegates)
[436] Elected members of the Democratic National Committee (including the Chairs and Vice-Chairs of each state's Democratic Party)[2]

This is the anti-democratic, machine politics holdover of the Democratic Party candidate selection apparat. They are all completely isolated from the voters and vote as they damn well please, regardless of the popular vote. That, at any rate, is the plan and the purpose behind this elitist arrangement. To a degree, they are right.

The first group, Bill, Al, Debbie and all that crowd can't be touched. They no longer answer to anybody and no longer give a shit what you think, if, in fact, they ever did. The sole exception is Debbie, and we can write her off for sure.

The next 3 groups, however, can be pressured with threats not to fund their re-election campaigns and even threatening things like supporting efforts to primary them or withholding your vote from them. Those not up for re-election soon need to be told that you will remember, that it will be on your fridge and dresser top. Those hoping for higher office are subject to similar threats. Find out where your governor, Senators and Rep stand (if Dems) and give them an earful. Maybe even organize a letter or e-mail campaign to make sure that they know:
1) Bernie is the people's choice
2) They are in deep shit as to future elections if they vote the wrong way
3) You will be watching and you will follow up.

Obviously, if your Senator is a complete tool, like DiFi, you know that she won't listen or give a shit, but make at least one call or send at lest one letter anyway. Ditto Blue Dogs. No matter how much certain people on DK decry calling them conservatives, that's what they are, big time, and good luck with that, but make some sort of effort anyway.

The last group contains some people you can get to also, like your state party chair. Find out how to apply leverage to these people and do so.

WE don't really need this vestige of oligarchy, but it is there. What we therefore must do, is to try to bend all those except the "Distinguished Party Leaders" to the popular will.