| Sample | Sanders (D) | Clinton (D) |
|---|
IA: Quinnipiac University
Jan 25-31, 2016 | 919
Likely | 49% | 46% |
IA: Emerson College
Jan 29-31, 2016 | 300
Likely | 42.67%
128 | 50.67%
152 |
IA: Selzer & Company, Bloomberg, Des Moines Register
Jan 26-29, 2016 | 602
Likely | 42% | 45% |
IA: Public Policy Polling
Jan 26-27, 2016 | 851
Likely | 40% | 48% |
IA: Gravis Marketing, One America News Network
Jan 26-27, 2016 | 810
Likely | 42% | 53% |
IA: Monmouth University Polling Institute
Jan 23-26, 2016 | 504
Likely | 42% | 47% |
IA: Marist Institute for Public Opinion, NBC News, Wall Street Journal
Jan 24-26, 2016 | 426
Likely | 45% | 48% |
IA: Quinnipiac University
Jan 18-24, 2016 | 606
Likely | 49% | 45% |
IA: American Research Group
Jan 21-24, 2016 | 400
Likely | 48% | 45% |
IA: Iowa State University
Jan 5-22, 2016 | 356
Registered | 45% | 47.4% |
IA: YouGov, CBS News
Jan 18-21, 2016 | 490
Likely | 47% | 46% |
IA: Anderson Robbins Research, Shaw & Company Research, Fox News
Jan 18-21, 2016 | 423
Likely | 42% | 48% |
IA: ORC International, CNN News
Jan 15-20, 2016 | 280
Likely | 51% | 43% |
IA: Emerson College
Jan 18-20, 2016 | 258
Likely | 36.43%
94 | 51.94%
134 |
IA: Douglas Fulmer & Associates, KBUR-AM (Burlington, Iowa), Monmouth College
Jan 18-19, 2016 | 570
Likely | 42.42%
224 | 51.52%
272 |
IA: Loras College
Jan 13-18, 2016 | 500
Likely | 29.8%
149 | 58.6%
293 |
IA: Gravis Marketing, One America News Network
Jan 11-12, 2016 | 461
Likely | 36% | 57% |
IA: Public Policy Polling
Jan 8-10, 2016 | 580
Likely | 40% | 46% |
IA: Selzer & Company, Bloomberg, Des Moines Register
Jan 7-10, 2016 | 503
Likely | 40% | 42% |
IA: Quinnipiac University
Jan 5-10, 2016 | 492
Likely | 49% | 44% |
IA: American Research Group
Jan 6-10, 2016 | 400
Likely | 47% | 44% |
IA: Marist Institute for Public Opinion, NBC News
Jan 2-7, 2016 | 422
Likely | 45% | 48% |
IA: Gravis Marketing
Dec 19-21, 2015 | 418
Likely | 31% | 49% |
IA: YouGov, CBS News
Dec 14-17, 2015 | 459
Likely | 45% | 50% |
IA: Quinnipiac University
Dec 4-13, 2015 | 727
Likely | 40% | 51% |
IA: Public Policy Polling
Dec 10-13, 2015 | 526
Registered | 34% | 52% |
IA: Loras College
Dec 7-10, 2015 | 501
Likely | 27.35%
137 | 58.88%
295 |
IA: Selzer & Company, Bloomberg, Des Moines Register
Dec 7-10, 2015 | 404
Likely | 39% | 48% |
IA: Anderson Robbins Research, Shaw & Company Research, Fox News
Dec 10, 2015 | 357
Likely | 36% | 50% |
IA: OvertimePolitics.com
Dec 4-8, 2015 | 433
Likely | 41.11%
171 | 51.44%
214 |
IA: ORC International, CNN News
11/28-12/6/2015 | 442
Likely | 36% | 54% |
IA: Monmouth University Polling Institute
Dec 3-6, 2015 | 405
Likely | 33% | 55% |
IA: Quinnipiac University
Nov 16-22, 2015 | 543
Likely | 42% | 51% |
IA: YouGov, CBS News
Nov 15-19, 2015 | 602
Likely | 44% | 50% |
IA: Morning Consult
Nov 10-16, 2015 | 211
Likely | 37.98%
79 | 55.77%
116 |
IA: Iowa State University
Nov 2-15, 2015 | 496
Registered | 27.8% | 49.5% |
IA: ORC International, CNN News
10/29-11/4/2015 | 498
Likely | 37% | 55% |
IA: Public Policy Polling
10/30-11/1/2015 | 618
Registered | 25% | 57% |
IA: Douglas Fulmer & Associates, KBUR-AM (Burlington, Iowa), Monmouth College
Oct 29-31, 2015 | 681
Likely | 31.72%
216 | 45.81%
312 |
IA: Gravis Marketing, One America News Network
Oct 26, 2015 | 273
Registered | 24.8% | 57.1% |
IA: Monmouth University Polling Institute
Oct 22-25, 2015 | 400
Likely | 24% | 68% |
IA: YouGov, CBS News
Oct 15-22, 2015 | 555
Likely | 41% | 42% |
IA: Loras College
Oct 19-22, 2015 | 500
Likely | 23.6%
118 | 61.6%
308 |
IA: Quinnipiac University
Oct 14-20, 2015 | 592
Likely | 40% | 51% |
IA: Selzer & Company, Bloomberg, Des Moines Register
Oct 16-19, 2015 | 402
Likely | 37% | 42% |
IA: Marist Institute for Public Opinion, NBC News, Wall Street Journal
Sep 23-30, 2015 | 348
Registered | 36% | 47% |
IA: Gravis Marketing, One America News Network
Sep 25-27, 2015 | 328
Registered | 30.6% | 39.5% |
IA: Public Policy Polling
Sep 18-20, 2015 | 494
Registered | 22% | 43% |
IA: YouGov, CBS News
Sep 3-10, 2015 | 646
Likely | 43% | 33% |
IA: Quinnipiac University
8/27-9/8/2015 | 832
Likely | 41% | 40% |
IA: Marist Institute for Public Opinion, NBC News
8/26-9/2/2015 | 345
Registered | 37% | 48% |
IA: Gravis Marketing
Aug 29-31, 2015 | 421
Registered | 16.9% | 45.1% |
IA: Loras College
Aug 24-27, 2015 | 502
Likely | 22.91%
115 | 48.21%
242 |
IA: Selzer & Company, Bloomberg, Des Moines Register
Aug 23-26, 2015 | 404
Likely | 30% | 37% |
IA: Suffolk University
Aug 20-24, 2015 | 500
Likely | 19.8%
99 | 53.8%
269 |
IA: ORC International, CNN News
Aug 7-11, 2015 | 429
Likely | 31% | 50% |
IA: Public Policy Polling
Aug 7-9, 2015 | 567
Registered | 25% | 52% |
IA: Gravis Marketing, One America News Network
Jul 29, 2015 | 236
Registered | 24% | 50.8% |
IA: Marist Institute for Public Opinion, NBC News
Jul 14-21, 2015 | 320
Registered | 26% | 55% |
IA: We Ask America, KBUR-AM (Burlington, Iowa), Monmouth College
Jun 27-29, 2015 | 1022
Likely | 20.16% | 62.82% |
IA: Quinnipiac University
Jun 20-29, 2015 | 761
Likely | 33% | 52% |
IA: Selzer & Company, Bloomberg, Des Moines Register
Jun 19-22, 2015 | 401
Likely | 24% | 50% |
IA: Morning Consult
5/31-6/8/2015 | 322
Likely | 12.11%
39 | 54.04%
174 |
IA: Selzer & Company, Bloomberg, Des Moines Register
May 25-29, 2015 | 437
Likely | 16% | 57% |
IA: Gravis Marketing, Townhall.com
May 28-29, 2015 | 434
Registered | 15% | 59% |
IA: Quinnipiac University
4/25-5/4/2015 | 692
Likely | 15% | 60% |
IA: Public Policy Polling
Apr 26, 2015 | 466
Likely | 14% | 62% |
IA: Loras College
Apr 21-23, 2015 | 491
Likely | 2.04%
10 | 57.03%
280 |
IA: Quinnipiac University
Feb 16-23, 2015 | 619
Likely | 5% | 61% |
IA: Marist Institute for Public Opinion, NBC News
Feb 3-10, 2015 | 321
Registered | 7% | 68% |
IA: Selzer & Company, Bloomberg, Des Moines Register
Jan 26-29, 2015 | 401
Likely | 5% | 56% |
IA: Loras College
Jan 21-26, 2015 | 261
Likely | 3.83%
10 | 48.28%
126 |