En route to his conclusions in “Media organizations are blowing their endorsements, Matthew Yglesias flags a study, “Political practitioners poorly predict which messages persuade the public,” by David E. Brookman, Joshua L. Calla, Christian Caballero and Matthew Easton at OSF Reprints. From the Abstract:

Recent research finds that political persuasion efforts often have limited effects. We explore a potential explanation for this finding: that political practitioners have poor intuitions about how to persuade. This would be surprising in light of longstanding theories that political elites can easily manipulate public opinion (Lasswell 1938) and the large sums spent to secure their expertise (Sheingate 2016)—but resonate with findings regarding the surprising limits of expert forecasts (Milkman et al. 2022; Tetlock 2005). In this paper, we evaluate how well political practitioners can predict which messages are most persuasive. We measured the effects of N = 172 messages about 21 political issues using a large-sample survey experiment (N = 67, 215 respondent-message observations). We then asked both political practitioners who work to persuade the public (N = 1, 524 practitioners, N = 22, 763 predictions) and laypeople (N = 21, 247 respondents, N = 63, 442 predictions) to predict the efficacy of these messages. We find that: (1) political practitioners and laypeople both perform barely better than chance at predicting persuasive effects; (2) once accounting for laypeople’s inflated expectations about the average size of effects, practitioners do not predict meaningfully better than laypeople; (3) these results hold even for self-identified issue experts and highly experienced practitioners; and (4) practitioners’ experience, expertise, information environment, and demographics do not meaningfully explain variation in their accuracy. Our findings have theoretical implications for understanding the conditions likely to produce meaningful elite influence on public opinion as well as practical implications for practitioners.

None of which bolsters confidence in the messaging skills of campaign strategists. That doesn’t mean campaigns should not bother seeking experienced political message crafters and strategists. But it does suggest that their messages should be subjected to rigorous review and more skepticism.

Many a campaign has run aground by emphasizing the wrong messages or poorly presenting the right ones. There’s no foolproof way for a campaign to hire the best messaging talent. Although likable candidates with lackluster messages have sometimes won elections, winning political campaigns would rather have message-crafters and strategists who have a good track record.