In the primary scheme of things, Nevada is not Iowa or New Hampshire - almost an afterthought by most campaigns. Relative to NH in particular, there's been little time there for the 'Bern' to have much impact. HC is pretty far out in front of Sanders; the polling is old, from December, but again not much going on in NV, until now, to turn that around. If it does, it would likely be more about the casino workers than college students - big difference between NV and NH cultures on the place of academics in the states. Interesting that the worker union hasn't endorsed Clinton.
A Sanders' upset in NV would be somewhat telling but not lethal to Clinton. On the other hand, a Clinton win, as projected, would tell us nothing.
SC is where there is the opportunity for a fatal blow against either candidate. If Sanders upsets Clinton there, its over. If Sanders loses but it is close, ala Iowa, then Super Tuesday will be red hot. If Clinton wins by something over 10%, its pretty much over for the 'Bern.'
On the GOP side, NV has much of the same attributes of not being much about anything - although it may show some of the hatred towards Trump by segments of the lower economic income folks. SC has some of the same asymmetrical outcomes for candidates. Assuming Christie drops out before SC and endorses Kaisch, then a SC win or even a strong second place behind Trump by Kaisch will end the bids of both Cruz and the Florida tag team of Bush and Rubio - one or more of them might stay in to save face but it will be over. Kaisch is not likely to win, this is the South - something the BernieBots are going to be educated upon. So a Trump win and a muddle for everyone else turns SC into a nothing burger and its on to Super Tuesday.
The only other potential killer here is if Cruz comes in first and it is not close; then it is over for Trump.
Pretty much as I've been calling it, including buying into the possibility of Mike's scenario of Trump's collapse as a 'Loser!' - indicating that scenario is still in play until SC. Also, HC could still lose the whole thing in SC depending on how it plays out (see above). On the other hand, if it plays out with what I see as the most likely scenario (i.e., significant HC and Trump win and muddled 2nd for GOP), then the big question for 2020 will be why both Iowa and NH go first and/or given such importance - White supremacy is so passe in so many ways.