Much crazier things have happened.
NH likes to offer up a different choice than IA, perhaps part of why hisorical polling indicates most NHers decide in the last 7 days.
If Trump bags IA and Rubio comes in with say 17%, then NH could flip in a week.
Rubio like others has been caught flat footed by Trump, but anything high teens will get the upstart narrative going.
My Rubio thing is largely about what I fear most, I think he could/would beat HRC, but not Trump, Cruz or Jeb.
January polls are full of all sorts of people who don't win nominations and don't become Presidents, but winning *both* IA and NH is formidable in historical terms.
Trump just polls so poorly in second choice polling that when the field begins to narrow the polling suggests everybody *but* him will benefit.