Feb 1 Iowa Democratic Presidential Caucus: Quinnipiac Clinton 46, Sanders 49, O'Malley 3 Sanders +3

Also relying on first-time Iowa likely Democratic Caucus participants, Sen. Bernie Sanders of Vermont has 49 percent, with 46 percent for former Secretary of State Hillary Clinton and 3 percent for former Maryland Gov. Martin O'Malley. Only 2 percent remain undecided and 14 percent of those who name a candidate say they might change their mind.

The key for both Trump and Sanders is first-time caucus goers:

Trump leads Cruz 40 - 22 percent among these first-timers, while Republicans who attended prior caucuses go 26 percent for Cruz and 25 percent for Trump;
Sanders tops Clinton 62 - 35 percent among Democratic first-timers, while Clinton leads 52 - 41 percent among voters who attended prior caucuses;
44 percent of Republicans and 38 percent of Democrats say this is their first caucus.


http://www.quinnipiac.edu/news-and-events/quinnipiac-university-poll/iowa/release-detail?ReleaseID=2320

Other polls show Sanders leads Clinton among Independents in Iowa, 56 to 44, which is why Bernie is a stronger GE candidate than Hillary