Harris’s Debate Performance Proved Persuasive in Grow Progress’s Rapid Message Test
Vice President Harris “only ever had one client: The People.” How did the people respond to what they heard on Tuesday night’s debate?
The Test
Rapid Message Testing from Grow Progress proves that Harris’s remarks during Tuesday night’s debate were persuasive through a randomized controlled trial, the platinum standard methodology for testing. Specifically, two clips of Harris’s debate responses made a statistically significant impact on viewers’ vote choice, with both messages moving battleground state respondents toward Harris by six percentage points.
On Wednesday, Grow Progress tested nine memorable moments from Tuesday night’s presidential debate to determine which messages persuaded viewers toward Harris. Messages ranged in length, tone, and topic.
The test asked respondents, “If the 2024 election for president were held today, would you vote for Kamala Harris, Donald Trump, or another candidate?”
In under seven hours, with a sample of 6,000 participants from battleground states, the results were actionable and clear. When Harris said that she “intends to be a president for all Americans,” her messaging proved persuasive for respondents and their presidential vote choice.
The Results
Both the 55-second clip, “Run on a Problem,” and the 32-second clip, “I’ll tell you- Kamala’s experience,” increased support for Harris by 6 percentage points.
“I’ll tell you- Kamala’s experience” showed participants a video of Harris from Tuesday night’s debate, as she said:
“I’ll tell you, I started my career as a prosecutor. I was a D.A, I was an Attorney General, a United States Senator, and now Vice President. I’ve only had one client: The people. And I’ll tell you, as a prosecutor, I never asked a victim or a witness, ‘Are you a Republican or a Democrat?’ The only thing I ever asked them was, ‘Are you okay?’ And that’s the kind of president we need right now. Someone who cares about you and is not putting themselves first. I intend to be a president for all Americans.”
“I’ll tell you- Kamala’s experience” also moved voters who self-identify as Independent, persuading them toward Harris by 11 percentage points. Other subgroups that were persuaded by this message include people over 55 years old, those with household incomes under $50K, and conservatives, by 11, 9 and 7 percentage points, respectively.
“Run on a Problem” was particularly effective with voters who self-identify as Independent, persuading them toward Harris by 13 percentage points. Other persuaded subgroups include urban residents, men, and suburban residents by 11, 9 and 7 percentage points, respectively.
Grow Progress found that a 57-second clip, “Abortion,” where Harris spoke on the effects of the Supreme Court ruling to undo the protections of Roe v. Wade, might persuade viewers toward Harris, but the effect size was too small to say that confidently.
Effects of Trump’s Remarks
Conversely, a 60-second clip of Trump’s closing statement, “Trump’s closing remarks – B,” calling America a “failing nation” and a “nation in serious decline” might have reduced Harris’s support, moving respondents 4 percentage points away from her. However, this effect is also too small to say that confidently.
The five additional messages tested, “Endorsement,” “fracking-reduce reliance on foreign oil,” “Donald Trump is weak,” “New Concepts of a Plan,” and “Trump’s closing remarks – A,” did not cause a detectable effect toward or away from Harris.
Conclusion
Grow Progress’s Rapid Message Test collected a representative sample of 6,000 respondents in a matter of hours. Only six hours after the Harris-Trump debate, Grow Progress customers were reviewing easy-to-interpret, actionable results in the Grow Progress platform. With less than 60 days left until the presidential election, can you afford not to get results as clear as these?Grow Progress sits at the intersection of science and empathy, empowering users to know what creative and messaging works — and why, so you can strategically grow your impact. Let’s get started—contact us at [email protected].
