From Gallup:

Barack Obama has now cut the gap with Hillary Clinton to 6 percentage points among Democrats nationally in the Gallup Poll Daily tracking three-day average, and interviewing conducted Tuesday night shows the gap between the two candidates is within a few points. Obama's position has been strengthening on a day-by-day basis. As recently as Jan. 18-20, Clinton led Obama by 20 points. Today's Gallup Poll Daily tracking is based on interviews conducted Jan. 27-29, all after Obama's overwhelming victory in South Carolina on Saturday. [Italics mine]

--Isaac Chotiner