IA - 2016 Democratic Presidential Primary: Hillary Clinton 46% - Bernie Sanders 32% - Martin O'Malley 5% - (KBUR/Monmouth College 11/03/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +14

IA - 2016 Democratic Presidential Primary: Hillary Clinton 57% - Bernie Sanders 25% - Martin O'Malley 7% - (PPP 11/02/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +32

IA - 2016 Democratic Presidential Primary: Hillary Clinton 62% - Bernie Sanders 24% - Martin O'Malley 3% - (Loras College 10/27/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +38

IA - 2016 Democratic Presidential Primary: Hillary Clinton 65% - Bernie Sanders 24% - Martin O'Malley 5% - (Monmouth Univ. 10/27/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +41

IA - 2016 Democratic Presidential Primary: Hillary Clinton 51% - Bernie Sanders 40% - Martin O'Malley 4% - (Quinnipiac 10/23/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +11

IA - 2016 Democratic Presidential Primary: Hillary Clinton 48% - Bernie Sanders 41% - Martin O'Malley 2% - (Des Moines Register/Bloomberg 10/22/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +7

IA - 2016 Democratic Presidential Primary: Hillary Clinton 33% - Bernie Sanders 28% - Joe Biden 22% - (NBC/WSJ/Marist 10/04/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +5

IA - 2016 Democratic Presidential Primary: Hillary Clinton 43% - Bernie Sanders 22% - Joe Biden 17% - (PPP 09/22/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +21

IA - 2016 Democratic Presidential Primary: Bernie Sanders 41% - Hillary Clinton 40% - Joe Biden 12% - (Quinnipiac 09/10/2015) chart & more info

Hillary Clinton
Bernie Sanders
  • Sanders +1

IA - 2016 Democratic Presidential Primary: Hillary Clinton 38% - Bernie Sanders 27% - Joe Biden 20% - (NBC/Marist 09/06/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +11

IA - 2016 Democratic Presidential Primary: Hillary Clinton 48% - Bernie Sanders 23% - Joe Biden 16% - (Loras College 09/02/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +25

IA - 2016 Democratic Presidential Primary: Hillary Clinton 37% - Bernie Sanders 30% - Joe Biden 14% - (Des Moines Register/Bloomberg 08/29/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +7

IA - 2016 Democratic Presidential Primary: Hillary Clinton 54% - Bernie Sanders 20% - Joe Biden 11% - (Suffolk Univ. 08/25/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +34

IA - 2016 Democratic Presidential Primary: Hillary Clinton 50% - Bernie Sanders 31% - Joe Biden 12% - (CNN/ORC 08/12/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +19

IA - 2016 Democratic Presidential Primary: Hillary Clinton 52% - Bernie Sanders 25% - Martin O'Malley 7% - (PPP 08/10/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +27