For obvious reasons, this kind of data is relatively rare, according to Broockman and Kalla: Few campaigns want to give outsiders carte blanche access to their operations, particularly when those outsiders might find their methods totally ineffective. But in many ways, it’s the most important kind of data available. It shows how actual voters and campaigns behave, rather than relying on theoretical surveys. The findings suggest that a lot of the time, energy, and money poured into traditional campaigning methods is wasted, and that the campaign operatives hawking tried-and-true tactics don’t have the evidence to back up their claims. It also casts doubt on the theory of the swing voter who can be persuaded with enough flyers, ad exposure, and conversations with earnest volunteers. In reality, Broockman and Kalla find, direct outreach is most effective at improving voter turnout, suggesting that campaigns should focus on getting their core supporters to the polls than reaching out to a mythical middle.

Before they published this paper, Broockman and Kalla ran into minor social-science fame when they debunked a major study showing that voters can be persuaded to change their views on same-sex marriage if they meet a gay or lesbian person. A short while later, the pair published their own paper on a campaign to change minds about transgender people, finding that persuasion is, in fact, possible. This new study suggests that intentionally curated, issue-specific persuasion campaigns may shift people’s views more easily than partisan political campaigns.

I spoke with Broockman and Kalla about their findings and the abject failures of most political campaigns. Our conversation has been edited for length and clarity. For more on this topic, read Molly Ball’s 2016 piece about the impotence of political consulting.

Emma Green: So, is political campaigning useless?

Joshua Kalla: The short answer is ‘no.’ There are lots of things that campaigning can accomplish. Two decades of research on voter registration and hundreds of field experiments show really cost-effective ways to increase turnout in the base.

But on persuasion, yes, we find that on average, there are very small effects.

David Broockman: Certainly, for those who hope to win elections or change each others’ minds, the conclusion should prompt a rethinking of the way to change minds.

Green: As you point out, a ton of money is spent every election cycle on television ads, directing-mail campaigns, canvassing operations, etc., which are all designed to persuade voters. How should we grapple with the fact that all this spending is largely ineffective?

Kalla: A lot of campaign operatives think there’s this big pool of moderate, undecided voters that we can spend money on to persuade them to our side. That strategy is probably not the right strategy. And we should be skeptical of big claims of persuasion.