Hillary Clinton has a real fight on her hands in Iowa, according to the latest poll by Selzer & Co for the Des Moines Register and Bloomberg News. Among 404 likely Democratic caucus-goers surveyed between August 23 and 26, Clinton is the first choice of 37 percent, followed by Bernie Sanders (30 percent), Joe Biden (14 percent), “not sure” (8 percent), “uncommitted” (6 percent), Martin O’Malley (3 percent), Jim Webb (2 percent), and Lincoln Chafee (1 percent. The poll’s margin of error is plus or minus 4.9 percentage points.

When respondents did not have the option of selecting Biden, Clinton was the first choice of 43 percent of respondents, while 35 percent picked Sanders.

The Selzer poll will worry the front-runner’s campaign, especially since two surveys of New Hampshire Democrats have now shown Sanders leading Clinton in the first primary state. Notably, Selzer found Sanders way ahead among caucus-goers under age 45 (50 percent to 27 percent), among first-time caucus-goers (43 percent to 31 percent), and among independents likely to participate in the Democratic caucuses (a 21-point lead, but I don’t see the numbers in the write-up by Jennifer Jacobs). Caucus-goers who are “feeling the Bern” are not driven by “anyone but Hillary” sentiment. Some 96 percent of respondents backing Sanders are doing so “mostly because [they] support him and his ideas”; just 2 percent said Sanders is their first choice mostly because they do not support Clinton.

The poll is horrendous news for O’Malley, who has worked his heart out campaigning in Iowa. Since 2013, he has visited the state fifteen times, spending all or part of 29 days here. Every time I’ve seen O’Malley in person, his stump speech has been well-received, but Sanders seized the progressive/liberal niche early. I don’t see a path for O’Malley to become viable in most of the state’s precincts. While he has been filling small and medium-sized venues, Sanders has been drawing ridiculously large crowds all over the state, most recently at the Des Moines Register’s Iowa State Fair soapbox. At events where there is no externally-imposed time limit, Sanders keeps the crowd’s attention for over an hour, not counting time he spends answering questions.

I will update this post as the Register publishes more data from the new survey. A separate post will cover the latest Selzer poll findings on Republican presidential candidates in Iowa.