Spencer Kimball, director, Emerson Polling
We did ask that question in a January 21 poll — at the time, we used seven announced candidates [which did not include Biden or Sanders].
Warren led with 43 percent of the vote, Harris was second, at 19 percent. It looks like since that poll, Harris has gained momentum; she has gone from 9 percent of the vote in December to 15 percent of the vote nationally and 18 percent in Iowa. Warren has hovered around 9 to 10 percent of the vote.
That January poll did not include Sanders, but I am not sure a Biden voter would go with Sanders. Instead, I think Warren and Harris have the most to gain and a dark horse candidate like Sherrod Brown could build a base off the 25 to 30 percent of the electorate who are currently leaning toward Biden.