Change Research seems to be more Sanders friendly than the other pollsters. But still, it does appear that Sanders has regained some support, while Biden has lost some from his peak.
If such a result were to occur, only Biden and Sanders would get delegates. For the race to not be just Sanders vs Biden, someone's gotta break the 15% marker in Iowa.
You gotta keep in mind though that, unless they changed this system (and I don't think they have), this applies at each caucus location with a possibility of switching. So if this result were to happen in a bellweather Iowa caucus location, the supporters of other candidates would get to switch around.
