Can it actually happen?
Speaking of momentum, a Sanders win refudiates both Nate Silver (a refudiation of him is almost always good, in my book) and Sam Wang as well.
And, the momentum issue could raise his win in New Hampshire — which then addresses the "superdelegates are all for Clinton" problem.
More good news elsewhere in polling, too. Sanders is above 25 percent now, nationally, with African-American voters. Still plenty of room for growth, but that figure, and the fact that it has a "surge" as well, may at least ease the "connecting with blacks" concern. (It would be nice to see something similar on Hispanic polling numbers pre-Nevada.) Dick Morris says the surge in Sanders' black numbers may be part of why Clinton is tying herself more closely to Obama.
Looking ahead in other ways? Just to New Hampshire and not Nevada or South Carolina, the DNC and Dancing With the Schultz have agreed, as the three candidates have already done, to both a town hall (Wednesday, 7 p.m. Central) and a debate (Thursday, 8 Central). Maddow (or a nickname I won't yet put here) could add a bit of spice to the debate, but only if — without any public endorsing by her, of course — if she's one of the feminists who in no way would vote for Clinton.
No matter, in general, though. Maddow was instrumental in getting more debates, not just now, but further out. And, that's what Democrats need. It also surely is what Sanders needs. But, that name recognition is already starting to boost; the momentum could boost more tonight.
GOP side? Let's call it a semi-draw.
Trump 29, Cruz 27, Rubio 16, Carson 8, Bush 4, Paul 4, Kasich 3, pocket lint after that. I don't think Trump will do better until I see that he's mastered the Iowa caucuses turnout.
Morris offers other insight, per my blogging that this isn't (yet) a two-person race. He notes that it starts becoming that on Super Tuesday, where half the available delegates come from states with 15 percent or 20 percent vote thresholds to get any delegates at all. (This winnowing is only on the GOP side, and is kind of like the superdelegate tool on the Dem side.) It rises to 60 percent of available delegates for the rest of March, after Super Tuesday.
Flip side is that the anti-Trump hatred is so high among so many that his bubble could still easily burst, and fringe-pollers have motivation to stay in if Trump shows any signs of trouble.