hi clo,
there was nothing magical about nate silver getting 100% right on the night last time. several other pollsters did too. actually i did also so the bar wasn't set too high. the polling made things very obvious especially once you removed rasmussen from the numbers (not so much a polling organisation as an organisation designed to skew the averages of the others). in the previous election, there were only two states in play on the night so again, it wasn't hard to get 48 right and the other two were a coin flip. (all of this assuming you aren't a fantasist republican pollster from romney's organisation).
click on iowa and new hampshire below:
http://elections.huffingtonpost.com/pollster/2016-iowa-presidential-democratic-caucus
http://elections.huffingtonpost.com/pollster/2016-new-hampshire-presidential-democratic-primary
as of today, you'd say sanders has a better than even chance in NH and a decent chance in Iowa. which makes things seem close.
but hc is still a long way ahead in the country.
http://elections.huffingtonpost.com/pollster/2016-national-democratic-primary
looks like bernie currently resonates in a narrow set of states.