Presidential Debate 1

Overnight National Research Among 1050 Likely Voters

On September 29th, 2020, the first presidential debate took place at Case Western Reserve University and Cleveland Clinic in Cleveland, OH.

Election 2020: First Presidential Debate


Mercury Analytics conducted an overnight survey including dial-tests of the first presidential debate between President Donald Trump and Democratic Presidential Candidate Joe Biden, which took place on September 29th, 2020 at Case Western Reserve University and Cleveland Clinic, Cleveland, OH.

The format for the first debate called for six 15-minute time segments dedicated to topics announced in advance in order to encourage deep discussion of the leading issues facing the country.

Chris Wallace, moderator of the first 2020 presidential debate, selected the following six topics for each segment: The Trump and Biden Records, The Supreme Court, Covid-19, The Economy, Race and Violence in our Cities, and The Integrity of the Election

The debate started at 9:00 p.m. ET and ran for 90 minutes without commercial interruption.

Mercury’s study tested the candidates’ performance among a national sample of n=1050 likely voters. Respondents were first asked a series of demographic questions followed by questions to help understand respondents’ current views on politics in America, and specifically on President Trump and Democratic Presidential candidate, Joe Biden.  Respondents were next shown one of six video clips from the debate featuring one of the 15-minute debate segments.

As participants watched the video, they moved a slider just below the video to the right the more strongly they agreed with what they were seeing and hearing, or to the left the more strongly they disagreed with the candidate. They also had the option to push a button that would identify a “GREAT MOMENT” or a moment when they felt “THAT’S NOT TRUE”.

Before the close of the survey, respondents were asked post-exposure questions to again assess their views on politics in the U.S.

For more information on Mercury’s dial-testing, click here, and for more technical information about the study, please contact Jordan Kraft or at 202-386-6322 x 322.



It was clear from the start of the debate that Donald Trump had no intention of thoughtfully discussing issues, of following agreed upon debate rules, or treating his opponent with respect. What he brought was a relentless series of mean-spirited attacks, filled with unsupported statements, misrepresentations, and angry bluster. While Joe Biden tried to present ideas, Trump’s constant attacks and personal insults made any substantive exchanges impossible, leaving Mr. Biden largely unable to answer, sometimes exasperated, sometimes angry.

Mercury’s research shows that Donald Trump’s behavior did not expand his base in any way, while Joe Biden’s adequate performance combined with Donald Trump’s argumentative, aggressive bullying and interruptions increased Biden support among ‘persuadables’, away from Trump.

Key Takeaways From the Debate:

  • 74% of Republicans give Trump a positive rating for his debate performance
    89% of Democrats give Biden a positive rating for his performance
  • 46% of Independents give Biden a positive rating
    35% of Independents give Trump a positive rating
  • 14% of Republicans give Trump a negative rating for his debate performance
    3% of Democrats give Biden a negative rating
  • 45% of Independents give Trump a negative rating while 30% of Independents give Biden a negative rating
  • After the debate, 10% of independents shifted toward Biden while 6% shifted toward Trump

Watch a compilation of a few moments of Donald Trump’s behavior.

Who DID Better in Each Segment

Q: Overall, who would you say did better in this video?
(Average calculated across six segments, ‘much’ or ‘somewhat’ better per candidate)

Who Did Better in the Debate Overall

DEBATE Performance OVERALL rating

Q: Overall, how would you rate Donald Trump’s / Joe Biden’s performance in this video?
(Averages calculated across six segments)


Trump Performance Overall Debate 1


Biden Performance Overall Debate 1

How Americans View One Another

Q: As a supporter of Donald Trump / Joe Biden / an undecided voter, how do you feel about Joe Biden / Donald Trump / Donald Trump and Joe Biden supporters? Please select all of the phrases that represent your feelings today.

Pre-Perception Presidential Debate 1

State of Politics in America

Q: Which of these statements best expresses your view of the state of politics in America? Which statement comes closest?

  • The divisions that exist between Republicans and Democrats are bad for America. I want to see Democrats and Republicans working together again solving our problems.
  • The divisions and fighting that exists between Democrats and Republicans is necessary to restore American greatness. Compromise between Democrats and Republicans has led to the problems we face.
  • Neither statement is true for me at all.
US Politics View Presidential Debate 1

How Americans Feel After Viewing the DEBATE

Q: After watching the video segments, how do you feel? Please select all that apply.


Q: If the next Presidential election was held today, who would you most likely vote for?
(Asked pre- and post-exposure. Calculated on a per respondent basis per the below.)

Trump Positive: Biden Shift to Trump + Biden shift to Neutral + Neutral shift to Trump
Biden Positive: Trump Shift to Biden + Trump shift to Neutral + Neutral shift to Biden
Unchanged: Trump still + Biden still + Neutral still

Support Shift Debate 1

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