Centering historically minoritized populations to design effective messages about an evidence-based policy to advance social equity

Researchers have raised concerns that messages describing racial disparities in social outcomes can reduce or polarize support for public policies to address inequality. We questioned this assumption by testing the impact of carefully crafted messages about child tax credit (CTC) expansion. We conducted two randomized message trials, study 1 using Prolific's nonprobability panel (<i>n</i> = 1,402) and study 2 using SSRS's Opinion Panel, a web-based probability sample of US adults (<i>n</i> = 4,483). Each study included comparably sized subsamples of Black, Hispanic, and White respondents from across the political spectrum. Study 1 compared six candidate messages to a control message and identified promising message strategies for replication. Study 2 compared two messages advocating for CTC expansion-one emphasizing policy benefits to all children (universalist) and the other describing benefits to all but even greater benefits to Black and Hispanic children (targeted universalist)-to a control message simply describing the policy. Primary outcomes were policy support and policy advocacy intentions. Study 2 tested preregistered hypotheses and conducted additional exploratory analyses using linear models. Both treatment messages produced greater policy support and advocacy intentions than the control message among Black and Hispanic respondents (Cohen's <i>d</i> 0.12 to 0.28). The universalist message also produced greater policy support than the control message among White respondents (Cohen's <i>d</i> = 0.16). The targeted universalist message did not reduce policy support or advocacy intentions among White and Republican respondents. Well-designed messages emphasizing policy efficacy can promote support for a redistributive tax policy across racial, ethnic, and political identities.