The third debate of the 2020 Democratic presidential campaign will air on Thursday, and performance expectations of the top contenders have shifted.

According to a new Insider poll, Democrats have strong confidence in Sen. Elizabeth Warren to win the debate, while expectations of the frontrunner, former Vice President Joe Biden, have waned dramatically.

Insider's most recent poll allowed respondents to choose up to three contenders they think will perform best in the upcoming debate. We found that over 57% Democratic voters expect Warren to shine on Thursday's ABC-hosted debate.

A majority of Democrats, at about 53%, also had faith in Sen. Bernie Sanders to outdo other competitors.

Here's how the ten candidates who qualified for the debate stacked up among those who plan to vote in their state's Democratic primary or caucus:

This will be the first debate in which Warren and Biden share a stage, and the contrast couldn't be clearer: Warren's expectations have risen since Insider's first debate expectations poll in June, while expectations of Biden — the most-favored debate winner from Insider's previous polling — have nose-dived from 62% in June to 38% in September.

Democratic voters have also slightly lost faith in Sanders' debate performance, from 58.5% in Insider's first poll to 52%, though he remains close behind Warren and significantly ahead of Biden.

Insider's poll results also show how seriously voters are taking the debates. Warren, whose debate performance has been highly praised, is emerging at the front of the pack, while her competitors are falling behind.

Despite a big boost in approval following an impassioned exchange with Biden in the first debates in June, Sen. Kamala Harris' momentum has slowed: she came in seven percentage points behind the former vice president in expectations for the upcoming debate.

Andrew Yang, meanwhile, has raised his profile by a large margin. Democratic voters' expectations for Yang's debate performance have more than doubled from Insider's polling prior to the second debates, from 6.7% to 13.7%. For the population at large, Yang's expectations have nearly doubled from 7.7% to 15.2%.

Among results from poll respondents overall, performance expectations for the three frontrunners have all seen slight declines since June. The general public has the highest anticipation for Sanders' debating this Thursday, with 44.1% of survey-takers expecting him to triumph, tailed by Biden and Warren with around 41% each.

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. Total 1,090 respondents collected September 6, 2019 - September 7, 2019, a margin of error plus or minus 3.07 percentage points with a 95% confidence level.

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