Suffolk University Poll Shows Clinton Dominating Democratic Field in Iowa

Even though 52 percent of likely Iowa Democratic presidential caucus voters say that the persistent controversy over Hillary Clinton’s email would hurt her in a November general election, they are backing her by a 34-point margin over her closest Democratic rival, according to a Suffolk University poll.

Clinton (54 percent) overwhelmed a field that included Vermont Sen. Bernie Sanders (20 percent), Vice President Joe Biden (11 percent), former Maryland Gov. Martin O’Malley (4 percent), and former Virginia Sen. Jim Webb (1 percent), while other candidates, including former Rhode Island Gov. Lincoln Chafee, received less than 1 percent. Nine percent of likely Democrats were undecided.

“There is a fierce loyalty to Hillary Clinton among likely Democratic caucus-goers in Iowa,” said David Paleologos, director of the Suffolk University Political Research Center in Boston. “Despite reports suggesting her vulnerability, these Democratic voters say they don’t believe she broke the law. They are sticking by her in large numbers, even though a majority believes the email scandal will hurt her in the general election.”

Potential Biden candidacy

The poll tested Joe Biden’s potential entrance into the Democratic fray, even though he has not reached a decision and plans to make a formal announcement of his intentions in a few weeks.

“Biden’s modest early support despite a favorability rating of more than 87 percent shows a lack of organization and funding, as he is not officially a candidate,” said Paleologos.

If Biden opts out of the race, his Iowa Democratic supporters would split 39 percent to Clinton, 29 percent to Sanders, and 18 percent to O’Malley, according to the poll’s subset of second-choices for the Democratic nomination.

Women keen on Clinton

Clinton’s strongest support was with women, who put her ahead by 43 points, 58 percent to Sanders’ 15 percent and Biden’s 13 percent.

“Historically, Democratic caucuses and primaries turn out a disproportionate amount of women, and Clinton is making the gender advantage work to her advantage,” said Paleologos.

State Department email issue

Fifty-two percent of Democratic voters said the email issue will hurt Clinton if she becomes the Democratic nominee, while 36 percent said it will not. Voters who prefer Clinton were split, with 44 percent saying the email question will hurt her and 44 percent saying it will not.

Asked if Clinton broke the law by using personal email while serving as Secretary of State, 9 percent said she did, while 76 percent said she did not, and 15 percent weren’t sure.

On the issue of honesty and trust, however, Sanders (32 percent) edged Clinton (29 percent) and Biden (18 percent). When voters were asked “which candidate best understands the problems facing people like you,” Clinton (39 percent) led Sanders (32 percent), and Biden (10 percent).

When non-Clinton voters were asked what is holding them back from supporting Clinton, 18 percent indicated that they “liked another candidate better.” Other responses included:


  • “untrustworthy/dishonest” (9 percent)
  • “email controversy” (9 percent)
  • “has a lot of baggage/issues” (5 percent)
  • “views on issues” (4 percent)
  • “she’s a Clinton” (3 percent)
  • “won’t make it” (3 percent)
  • “Wall Street/corporate” (3 percent)
  • “need change” (2 percent)
  • “not progressive enough” (2 percent)
  • “bad publicity/news” (2 percent)


Minimum wage

The poll showed overwhelming support for raising the minimum wage in increments to $15 per hour by the year 2020, with 85 percent of Democrats in favor and 11 percent opposed. A majority of Democratic voters (54 percent to 34 percent) would support an increase to $17.50 per hour by the year 2020, but they rejected raising the minimum wage to $20 per hour (51 percent to 34 percent).


The statewide survey of 500 likely Iowa presidential caucus voters was conducted August 20-24 using live telephone interviews of Democratic primary voter households where respondents indicated they were very or somewhat likely to attend their local presidential caucuses. The margin of error is +/-4.4 percentage points at a 95 percent level of confidence. Marginals and full cross-tabulation data is posted on the Suffolk University Political Research Center website: For more information, contact David Paleologos at 781-290-9310, [email protected].