Presidential Candidate Endorsements by Scientific Journal Decrease Trust in Science Especially for Moderate and Conservative Americans

Before the 2020 and 2024 U.S. Presidential elections, several scientific journals publicly endorsed the Democratic candidates or opposed the Republican candidate. We conducted three highly-powered, pre-registered online experiments (N = 6,281) to examine how these endorsements affected trust in science. Results revealed significant declines in trust in science, driven primarily by moderate and conservative Americans. These effects were observed across a range of outcomes, including general trust and distrust in science, trust in specific scientific recommendations, perceptions of its objectivity and impartiality, the perceived relevance of science to daily life, and, in some cases, beliefs in conspiracy theories. Notably, these findings highlight how motivated reasoning can amplify existing skepticism when individuals who already perceive science as aligned with opposing political ideologies read political endorsements from within the scientific community. Amidst increasing science-skepticism and politicization, journals must consider the unintended consequences of political endorsements on public trust and perceptions of impartiality.