have three other candidates who ossed the 50% mark, that's n rnie sanders, tht's pete buttigieg, and tundings kamala harris. so i look the rest of those with some upside potential.ge they'vt enough people who are interested in them to make potentially a forward move, and owe saw elizabeth warrensed in our last poll to do exactly that. >> reporter:. >> woodruff: and i want to ask you about that, ann selzer, because some folks would look at this and say, well, this iso rely good news for people polling in single digits, but i hearou saing there's still a movement. a large percentage of iowa voters are telng you they are democratic voters, are saying, you know, they may change their mind about who they're going toe for. >> well, that's exactly right, and there are two numbers i would pot you . first of all, the top three in single digits, that's 53% of the vote, so there's a lot of vote left to be had.o condly, we asked, if you had a first choice, is your mind made up, and that accounts for 20% of rll of the likely voters say i have a fist choice, and my mind is made up. so they either don't ha