Despite Clinton having a bounce-back in NH in 2008, she only won NV 51-45 and Obama won more delegates.
I think putting this "she needs to win by double-digits" isn't the actual standard. I think winning and it not being razor-close (ie not an IA redux) will be enough. She just needs to make sure she doesn't appear weak in the Latino vote.
The entrance polls in 2008 are pretty interesting.
In all seriousness, my analysis -
1 - This contains only Registered voters - Bernie is expected to win the majority of new registrations between now & caucus day (Or atleast a large chunk)
2 - Only 16% vote share of 18-29 age voters against 18% voting in Iowa (not very high)
3 - A huge , GIGANTIC 32% of the voters above the age of 65 - Seemed very unusual
4 - 59% of the voters are female - So no1 can blame of a sample benefiting Bernie
The demographic sample is incredibly favorable to Hillary. Noway 1 out of 3 voters will be above the age of 65.
If this poll is true, Bernie is likely leading by atleast 3-4% points
13% in 2008 were under 30
36% were over 65
59% were female
So... yeah.