Trumpism, climate and COVID: Social bases of the new science rejection

substantially more complicated models (six additional parameters in each equation), it does not improve fit. The categorical-predictor models yield almost the same pseudo R2 values and worse BIC. 6. Discussion Trumpism’s impacts on two existentially consequential cases of science rejection, climate change and COVID vaccination, reinforce its importance as an emergent sociopolitical iden- tity. Although Trump’s personal future is uncertain, his deep effects on US society are unlikely to go away soon; under some scenarios they could intensify. Even if support for Trump himself narrows, for example, elements of conspiracism and science rejection might become more pronounced among his core believers, or attach to new grievances and leaders. The potentially global consequences of science rejection by a leading US political party underline the need for continued scrutiny. An intervening-variable framework along the lines of Fig 1, and proposi- tions supported by this analysis, could apply in studies of Trumpism beyond Trump. Lower trust in scientists (generically) among US conservatives is well known [94–96], although sometimes coexisting with abstract expressions of trust in science itself. Surveys find liberal/conservative divisions across many specific fields besides climate and COVID—includ- ing disbelief in central propositions of biology, geology and astronomy; and lower trust in sci- entists regarding nuclear power, genetically modified organisms, environmental protection, renewable energy, forest management, and vaccination long before COVID [53,97–99]. Con-

servative (and Trump-supporter) distrust of epidemiologists emerged quickly during the 2016 Zika pandemic [32,100]. Bias across these major fields runs consistently in the same direction —contrary to early hypotheses that there might be an opposite bias among liberals against vac- cines, nuclear power or genetically modified organisms. In contrast to most surveys, some experimental studies have reported items where liberals express greater skepticism—but that seems most common with counterfactual experimental prompts such as an invented scientific consensus that nuclear power is the most efficient form of alternative energy [101], or a fic- tional expert asserting that carrying concealed handguns decreases violent crime [102]. The breadth of real fields where science rejection occurs tends to undercut explanations based on scientific content in particular cases. Examples of content-based explanations include religious objections to science on evolution or the age of the Earth [103], or a liberal/conserva- tive split on impact science vs. production science (e.g., science pointing out environmental or occupational health risks, vs. science that advances manufacturing or commerce) [104–106]. Disproportionately conservative science resistance across many fields also argues against explanations based on real conduct by scientists themselves, who in most areas are little known to the public. Hamilton and Safford [18] considered alternative hypotheses as they might apply to one specific case, the rapid fall of trust in the US Centers for Disease Control (CDC) observed

among Republicans during early months of the COVID-19 pandemic. They concluded that only elite cues—specifically, changing pronouncements from Trump—could explain the abruptness and scale of partisan decline. Other studies have found significant Trump-sup- porter effects regarding climate, COVID and other topics [14,19,31–33]. Trumpism exacer- bates the broader trend toward conservative science rejection across many fields. Matt Motta and coauthors recently studied “canine vaccine hesitancy” (CVH), a rising dis- trust among dog owners regarding long-established vaccines against rabies [107]. Their 2023 survey of 2,200 US adults found surprisingly high levels of doubts and non-vaccination, with concerns borrowed from misinformation about human vaccines. For example, 37 percent believed that vaccination might cause pets to develop autism. Political dimensions of this PLOS ONE Trumpism, climate and COVID PLOS ONE | https://doi.org/10.1371/journal.pone.0293059 January 10, 2024 12 / 20