clock menu more-arrow no yes mobile

Filed under:

Study suggests Democrats should be running more ads about Biden, fewer about Trump

It’s almost impossible to change minds about the president.

A Democratic ad attacking Trump.
Priorities USA

Groups that want to defeat President Donald Trump have already spent a decent chunk of money making and airing negative ads making the case Trump should not be reelected. A new survey experiment by political scientists David Broockman and Joshua Kalla suggests that this is probably a mistake. People have already heard a lot about Trump, and neither pro-Trump nor anti-Trump ads are very effective at shifting people’s perceptions of him.

By contrast, despite his 48 years in national politics, Joe Biden is not as well known. Both pro-Biden and anti-Biden messages can move the needle: People who don’t like Trump can still be convinced to dislike Biden, and people who do like Trump can be convinced that Biden is okay.

The Trump campaign is spending most of its money on anti-Biden ads, trying to push down his numbers. Trump is losing pretty badly anyway, which underscores the general point that it’s really hard to persuade people with campaign messages. But at the margin, Trump’s campaign is investing in the right thing — shifting perceptions of Biden. If Democrats want to maximize their odds of winning, they’d be well advised to do the same — invest money in ads promoting the former vice president.

The research: People already hear a lot about Trump

Voters are inundated with information about Donald Trump. Back before he was a politician, Trump was a master of securing publicity for himself. He dominated the airwaves during the 2016 campaign, and since ascending to the Oval Office has been a near-constant presence in American life.

Polls show that voters hear far more about Trump than they do about Biden, and Biden is frequently mocked or critiqued for being invisible. Some Democrats fret about this, while some analysts tell them not to worry, but it’s clearly true that Trump is a much more frequent presence on live television and the subject of many more articles.


Broockman and Kalla conducted a large experiment in early 2020 to test whether this gap in background level of information makes a difference. They found that it did. They took a sample of 291 messages — some pro-Trump, some anti-Trump, some pro-Biden, and some anti-Biden — and subjected a very large sample of 131,742 people to a random selection of two messages each out of the 291.

They found that “both positive and negative messages about Biden have significantly larger effects on stated vote choice than either positive or negative messages about Trump.” What’s more, even the tiny impact of the Trump messages may be a kind of statistical illusion.

There are two other points of particular interest:

  • Specific pro-Biden messages are more effective than vague messages.
  • Anti-Trump messages didn’t shift voting intention even though they often were effective at shifting perceptions of Trump on the specific subject of the ad.

They interpret this research as showing that there is a kind of saturation effect going on with voters. It’s not that you can’t tell people anything new about Trump, it’s just that telling them new things doesn’t make a difference at this point about whether or not they support him. By contrast, new information about Biden shifts votes. These are academics, so the paper mostly situates itself in a larger scholarly literature whose point is to debate different theories about how political advertising works. They aren’t campaign consultants offering advisc to either campaign on how to win.

But a news consumer may be more interested in a different angle: Democrats are making bad decisions (so far) about how to spend their money.

Democrats are blowing a lot of cash on anti-Trump ads

Democrats really hate Donald Trump. In fact, he is widely seen in many quarters as a kind of existential violation of the social contract or basic human decency. Perhaps as a result of this, Democrats and Democrat-aligned groups are running tons of ads explaining how terrible Trump is. Eight times as many anti-Trump TV ads as pro-Biden ones, in fact.

Broockman and Kalla

In a focus group, these ads may succeed at their mission — to inform people that Trump is despoiling the environment, to let people know about some forgotten act of Trumpian corruption or misconduct, to highlight the failings of Trump’s pandemic response. But the experiment shows is that even if you can give people new information about Trump, it doesn’t change their minds. People are dug-in on Trump.

One problem Democrats may have in acting strategically: An ad touting Biden’s support for a minimum wage increase, or his plan to double Pell Grants, or his legislative work on the Violence Against Women Act, or the way he commuted back-and-forth every day from DC to Delaware to be present in the lives of his young kids would necessarily be kind of earnest and boring.

Democratic ads are made by committed Democrats, the money to air them is raised by committed Democrats from committed Democrats, and the decisions about which ads to invest in are also made by committed Democrats. Committed Democrats probably find anti-Trump ads to be inherently more entertaining, and the mining of Trump’s record of saying and doing terrible things to be more rewarding than talking up Biden’s fairly banal Democratic Party policy ideas.

But banal ads can work well. In the context of Doug Jones’s race against Roy Moore, who courted controversy and has been accused of preying on girls and young women, experiments show the most effective ad by a Jones-aligned group was a super-boring spot about how he thinks education is good. Democratic ad testers have also told me that incredibly banal pro-Jones ads talking about how he has a family and goes to church performed very well. People didn’t know anything about him, and some Alabamians have negative background stereotypes about Democrats, so just depicting Jones as a typical middle-class Southern person moved the needle.

And to really beat Trump, Democrats may need to set aside their hatred of the guy, and instead focus more on some boring puff pieces about Biden.