Why are there a million GOP polls and very few Dem. Polls? Do pollster care about the democratic race?
Because we all know who'll win the Democratic nomination. The Republican one is more interesting. It's not that interesting to see whether Hillary will beat Sanders by 40 or 50% in South Carolina.
With Sanders cutting Hillary's national lead from 34 to 19, I wouldn't be so sure, expecially since Clinton imploded in 2008.
One poll showed Sanders cutting into her lead, the rest have been very stable. One could argue that the prior NBC/WSJ poll was an outlier and this is them falling back in line with the rest.