POLL: Democrats' belief Joe Biden can beat Trump took a massive 14-point hit after disastrous Iowa caucus

• Just over 50% of Democratic voters believe Joe Biden would beat President Donald Trump in a general election, according to a new Insider poll that shows their belief in Biden's electability is dropping.
• Since Insider began polling on the question in August 2019, Democratic voters have shown a high level of trust in Biden's "electability," or his ability to beat Trump in a general election.
• Biden's latest plummet in the poll could reflect uncertainty among Democratic voters about the strength of his electability.
• Visit Insider's homepage for more stories.

Just over 50% of Democratic voters believe Joe Biden would beat President Donald Trump in a general election, according to the Insider poll conducted in the aftermath of Biden's disastrous showing in the Iowa Caucus, down from an average of 64% over the past six months.

The former vice president has campaigned on a promise to return America to the pre-Trump status quo, an era that Biden hopes to lead in an emphasis on moderate Democratic politics and bipartisanship.

The latest poll suggests that Democratic voters have less faith in Biden's ability to beat Trump than anytime before. For the past several months, Insider has been conducting a series of SurveyMonkey Audience polls to gauge Americans' opinions on 2020 Democratic primary. You can download every poll here, down to the individual respondent data. (Read more about how the Insider Democratic primary tracker works here).

The most recent poll was conducted February 8 to 9 and had 1,013 respondents, 414 of whom said they were registered to vote and would likely do so in the Democratic primary.

That poll was conducted in the aftermath of an Iowa Caucus where Biden came in a distant fourth and a Friday evening debate where the former vice president all but conceded the state of New Hampshire in his opening salvo. It found that 50.1% of Democratic respondents believe Biden would beat the current president head-to-head.

Though still quite high, Biden has presented himself as the candidate with the name-recognition and experience to defeat Trump, and made this argument the centerpiece of his campaign. The fall in support should be setting off alarm bells in the former vice president's campaign. Over the six month period from August to January, across 18 Insider/Surveymonkey Audience polls, Biden averaged 64.3% of Democratic respondents who believed he'd beat Trump.

Even less than a week before the Iowa caucuses, Biden showed strong electability numbers, with 64.1% of Democratic voters saying he would beat Trump in November, according to Insider data.

The percentage of Democrats who specifically said they think the former vice president would lose also jumped in the poll compared to his overall average; over the past six months, just 22% of Democrats aware of Biden thought he'd lose to Trump. In the most recent poll post-Iowa, that registered as 31.2%, a nine-point jump.

Democratic voters have shown a high level of trust in Biden's "electability," his claim he can beat Trump in a general election. In November, then-Mayor Pete Buttigieg of South Bend, Indiana, began surging in Iowa. Massachusetts Sen. Elizabeth Warren's support began to slide, and Vermont Sen. Bernie Sanders shocked the political establishment with a second wind that has propelled his campaign.

Through the last quarter of 2019, Biden's support largely remained steady.

The recent shifts in voters' preferences has largely been reflected in the Iowa caucuses results, which show Buttigieg just edging out Sanders for first place according to still-disputed allocations of delegates, with Warren in third. But Biden's catastrophic fourth place position was unforeseen.

The latest Insider poll of a Biden-Trump match-up, which comes on the heels of the Iowa results, could reflect broad uncertainty among Democratic voters about the strength of Biden's electability.

With Biden sliding, Buttigieg appears well-positioned to take the mantle of most-electable-centrist. He is showing strong support in New Hampshire, whose primary is scheduled for Tuesday, February 11.

As Warren's support dips further, Sanders has become the standard-bearer for progressive Democrats. He is projected to win the New Hampshire primary with 28%, compared to Buttigieg's second place finish with 23% of votes, according to FiveThirtyEight.

• Read more:
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SurveyMonkey Audience polls from a national sample balanced by census data of age and gender. Respondents are incentivized to complete surveys through charitable contributions. Generally speaking, digital polling tends to skew toward people with access to the internet. SurveyMonkey Audience doesn't try to weigh its sample based on race or income. A total of 1,083 respondents were collected January 22, 2020, a margin of error plus or minus 3 percentage points with a 95% confidence level.