IA - 2016 Democratic Presidential Primary: Hillary Clinton 46% - Bernie Sanders 40% - Martin O'Malley 8% - (PPP 01/12/2016) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +6

IA - 2016 Democratic Presidential Primary: Bernie Sanders 49% - Hillary Clinton 44% - Martin O'Malley 4% - (Quinnipiac 01/12/2016) chart & more info

Hillary Clinton
Bernie Sanders
  • Sanders +5

IA - 2016 Democratic Presidential Primary: Bernie Sanders 47% - Hillary Clinton 44% - Martin O'Malley 3% - (ARG 01/11/2016) chart & more info

Hillary Clinton
Bernie Sanders
  • Sanders +3

IA - 2016 Democratic Presidential Primary: Hillary Clinton 49% - Bernie Sanders 42% - Martin O'Malley 5% - (Mason-Dixon 01/10/2016) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +7

IA - 2016 Democratic Presidential Primary: Hillary Clinton 48% - Bernie Sanders 45% - Martin O'Malley 5% - (NBC/WSJ/Marist 01/10/2016) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +3

IA - 2016 Democratic Presidential Primary: Hillary Clinton 51% - Bernie Sanders 40% - Martin O'Malley 6% - (Quinnipiac 12/15/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +11

IA - 2016 Democratic Presidential Primary: Hillary Clinton 59% - Bernie Sanders 27% - Martin O'Malley 4% - (Loras College 12/15/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +32

IA - 2016 Democratic Presidential Primary: Hillary Clinton 52% - Bernie Sanders 34% - Martin O'Malley 7% - (PPP 12/15/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +18

IA - 2016 Democratic Presidential Primary: Hillary Clinton 48% - Bernie Sanders 39% - Martin O'Malley 4% - (Des Moines Register/Bloomberg 12/14/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +9

IA - 2016 Democratic Presidential Primary: Hillary Clinton 50% - Bernie Sanders 36% - Martin O'Malley 5% - (FOX News 12/13/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +14

IA - 2016 Democratic Presidential Primary: Hillary Clinton 55% - Bernie Sanders 33% - Martin O'Malley 6% - (Monmouth Univ. 12/08/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +22

IA - 2016 Democratic Presidential Primary: Hillary Clinton 54% - Bernie Sanders 36% - Martin O'Malley 4% - (CNN/ORC 12/07/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +18

IA - 2016 Democratic Presidential Primary: Hillary Clinton 50% - Bernie Sanders 28% - Martin O'Malley 3% - (Iowa State Univ./WHO-HD 11/30/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +22

IA - 2016 Democratic Presidential Primary: Hillary Clinton 51% - Bernie Sanders 42% - Martin O'Malley 4% - (Quinnipiac 11/25/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +9

IA - 2016 Democratic Presidential Primary: Hillary Clinton 55% - Bernie Sanders 37% - Martin O'Malley 3% - (CNN/ORC 11/06/2015) chart & more info

Bernie Sanders
Hillary Clinton
  • Clinton +18