The supporters of the three Democratic frontrunners in the 2020 presidential primary really don't like Pete Buttigieg, according to Insider's polling.

Fans of former Vice President Joe Biden, Sen. Elizabeth Warren, and Sen. Bernie Sanders all like Buttigieg much less than the typical Democrat does.

Sen. Bernie Sanders' base is especially averse to Buttigieg. Compared to Democrats on the whole, they have less affinity for him than any other Democratic candidate.

Sanders has run a grassroots campaign without the support of any billionaires, while Buttigieg has the highest number of billionaire donors in the field.

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The supporters of the frontrunners in the 2020 Democratic primary have something surprising in common: They really aren't fond of Pete Buttigieg, the 37-year-old presidential candidate who is mayor of South Bend, Indiana.

Since December 2018, Insider has been conducting national polls on a near-weekly basis, asking respondents who plan to vote in their state's Democratic primary or caucus who they would be satisfied with as the party nominee for president.

Results found that those would be satisfied with Sen. Elizabeth Warren of Massachusetts, former Vice President Joe Biden, and Sen. Bernie Sanders of Vermont, all favored Pete Buttigieg significantly less than the typical Democrat does.

Buttigieg is well-liked, but lacks confidence from key voters

Buttigieg is considered to be a likable candidate. Insider's most recent eight polls, surveyed from mid-July through September, found that he has an average favorability of 48.5% — trailing only Sen. Kamala Harris of California and the three frontrunners.

But Buttigieg's appeal hasn't charmed Warren, Biden, and Sanders' constituents. Biden's supporters had 14.2 percentage points less affinity for Buttigieg, and Warren's had 6.3 percentage points less. Among Sanders supporters, Buttigieg was less favored by a hefty 18.2 percentage point difference compared to Democrats on the whole: a higher margin than the Sanders constituency had for any other rival.

Tellingly, the vast majority of self-reported Democratic voters don't have faith in Buttigieg to lead the party to victory in 2020. Only 17% of respondents said that they thought Buttigieg could defeat President Donald Trump in an election in Insider's latest poll — around three times less than the proportions of those who thought Warren, Biden, or Sanders could win.

An elite resume and bigwig backers could be deal-breakers

Buttigieg's candidacy differs from the three frontrunners' in several major ways. Most notably, he's young — nearly half the age of Warren, Biden, and Sanders, who are all septuagenarians.

Insider previously polled American adults on the qualities and accomplishments they want in a presidential candidate, and being under 50 years of age was considered a highly positive attribute — but Buttigieg's resume may turn off key voters in other ways. For one, his youth means that he has little government experience compared with many of his rivals.

More detrimental, though, are aspects of Buttigieg's elite background. His stint at the top consulting firm, McKinsey & Company, which has been mired in scandals related to corruption and support of authoritarian regimes, is considered a con among Democratic voters, who reported frowning upon management consulting experience when evaluating candidates.

Buttigieg also enjoyed an affluent upbringing — a trait that was perceived highly negatively by those surveyed, and a trait that none of the three top contenders share. His campaign has been backed by more ultra-wealthy contributors than any other contender's, with nearly two dozen billionaire donors, according to a report from Forbes. By contrast, Biden has 13 billionaire donors, and Warren has two.

Sanders, who has run a grassroots campaign that boasts significantly more donors, with greater geographic diversity than any other candidate, has no billionaire donors. That detail alone might explain why his supporters are so skeptical of Buttigieg.

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