Poll: Hillary Clinton still a strong frontrunner in Iowa

Democratic presidential candidate Hillary Clinton speaks about college affordability during a town hall meeting in Dubuque, Iowa, Aug. 14, 2015.

Reuters/Joshua Lott

Hillary Clinton has had a rough month. The controversy over her private email is burgeoning, not fading. Her strongest primary rival, Vermont Sen. Bernie Sanders, continues to gather steam. And the chatter surrounding Vice President Joe Biden's potential bid has taken on a real sense of urgency.

A Suffolk University poll released Tuesday, however, underscored the main reason Clinton remains a strong frontrunner for the Democratic nomination: Democratic voters, by and large, are still standing behind her.

The survey showed Clinton, a former secretary of state, with a commanding lead in Iowa, earning support from 54 percent of likely Democratic caucus-goers in the state. Twenty percent backed Sanders, 11 percent backed Biden, and 4.4 percent backed former Maryland Gov. Martin O'Malley.

Of those who didn't support Clinton, 18.2 percent said they simply preferred another candidate. Only 8.7 percent said she was untrustworthy or dishonest, and an identical number cited the controversy surrounding her emails.

Seventy percent of respondents said they weren't bothered by the email flap, while 26 percent said they were. Fifty-two percent said they expect it to hurt her in the general election, however, while 36 percent said it won't make a difference.

The poll surveyed 500 respondents between August 20 and 24, and the results have a margin of error of plus or minus 4.4 percent.

A CBS News poll released earlier this month found Clinton at 58 percent among Democratic voters nationwide. Sanders was a distant second at 17 percent, and Biden came in third at 11 percent.