I think it’s possible because of how tight the second tier is. Anyone of five candidates could be 2. The question is is it a strong 2,’or a distant 2 with 3,4 and 5 all within a point or two. No matter what, unless Jeb is buried in NH they will spin it as a “win” and his campaign is resurrected and off to the races. SC is their “firewall”. Kasich won’t go any further than NH as the next several states are hostile territory. Rubio will be close and Cruz will do better in the south. It depends on how much momentum, if any, Trump gets if he wins NH. When the expectations are so high (see Iowa) no matter how well he does, it’s not good enough. He is a first time politician never have running a campaign, in unfriendly territory for an east coaster, and he placed a respectable second and has one less delegate than the first place guy who had “home field” advantage, and it was viewed as a “loss”.
CNN said last night that if Trump didn’t win by at least 10% then it would be considered a loss. That’s the latest talking point.