The poll, conducted entirely since Sanders and Trump won landslide victories in New Hampshire, included interviews with just 245 likely Republican caucus-goers and 282 likely Democratic caucus-goers. It finds that Clinton is up 48 to 47 over Sanders, with a margin of error of three percentage points.
That would seem to verify what local Democrats have seen as a surge of new support for Sanders, who barnstormed the state last weekend and now has 12 local campaign offices to Clinton's seven. In January, the Clinton campaign told reporters that she was 25 points ahead of the challenger. It has not revealed polling since then, though Democrats suspected the lead had fallen to single digits after the New Hampshire primary this month.
The CNN-ORC result also mirrors a survey from TargetPoint, paid for by the Washington Free Beacon, a conservative news site, which Democrats quickly dismissed as an attempt to skew the caucuses.
"Why on earth would a far-right conservative website have a Republican firm poll Nevada’s Democrats in a race that’s seen as impossible to poll?" MSNBC's Rachel Maddow asked last week. "They couldn’t possibly be trying to influence that race, could they? Or trying to influence perceptions of that race? I don’t know."
The Republican side of the poll is, remarkably, the first look at that race by a news organization's pollster since the last CNN-ORC poll in October. The latest CNN-ORC poll finds Donald Trump leading the field with 45 percent, up seven points since last year, while Sen. Marco Rubio (R-Fla.) and Sen. Ted Cruz (R-Tex.) have climbed from single digits to 19 percent and 17 percent respectively. Neither has polled as close to Trump as Ben Carson had in October; since then Carson's support has tumbled from 22 to 7 percent.
The follow-up questions reveal the sources of Trump's strength, as well as the weakness that has every Republican strategizing about how to beat him. Strong majorities say that Trump has the best chance of winning the election (56 percent), is "most likely to change Washington" (64 percent), and would do the best job fighting the Islamic State (55 percent) and illegal immigration (58 percent). Yet just 28 percent of Republicans say Trump is closest to them on social issues.
That gives hope to Republicans who want to end Trump's run on Super Tuesday, on March 1. But it also challenges the impression that the better-organized campaigns of Rubio and Cruz were fighting for the win in Nevada. Both have campaign offices in the state, and Rubio briefly lived there. If Trump does not fall apart in South Carolina, none of his rivals have an obvious strategy for making up a 26-point or 28-point polling deficit in the three days between that primary and the Nevada caucuses. And while the state is difficult to poll, surveys in 2012 correctly found that former Massachusetts governor Mitt Romney had a commanding lead among Republican candidates.