so let's talk about that with cnn's senior political correspondent brianna keilar and cnn senior washington correspondent joe johns. brianna, first to you. tell us more about these polls. >> well, this is a poll, carol, that a lot of political observers are keenly soerveing. they've been sort of anxious for a des moines register poll because the pollster who does this poll actually is really seen as someone who pulls out the gold standard when it comes to numbers. this is something people are really looking at. 42 points hillary clinton, 40 bernie sanders. so you see the race tightening. but what's interesting when you look at the shift here from last month, it might not be so much that people are feeling the burn as they aren't feeling hillary clinton because she has actually dipped in the polls. and you see those undecideds, 14%, that is actually a huge jump of people who are uncommitted -- pardon me, from last month. as you can see there. now, bill clinton on the campaign trail, he's actually downplaying not just this poll certainly, but the number of polls that we have seen of the