How Does Topical Diversity Affect Source Credibility? Fact-Checking Coverage of Politics, Science, and Popular Culture

News sources that correct misinformation seek to foster an informed citizenry and promote democratic accountability. One such effort is being made by fact-checking sites across the globe. However, public trust in these outlets remains limited. Is their politics-focused coverage one factor behind the limited trust? Politics-focused coverage highlights partisan competition, which can harm credibility by activating identity-protective biases or resistance to persuasive intent. Prior research suggests depoliticized contexts can help mitigate defensive psychological tendencies in news source assessments. Thus, a potential approach to build broad-based trust could be to broaden the scope of coverage to include nonpolitical topics. Through a preregistered survey experiment in the United States, I test how the topical scope of coverage affects source credibility perceptions. Compared to politics-focused coverage, science-focused coverage improves credibility assessments. Focusing solely or partially on popular culture topics such as entertainment, sports, and lifestyle reduces source credibility. The effects of nonpolitical coverage on source credibility perceptions are similar across partisan groups. The results suggest the public shares the notion that serious public affairs coverage is central to reputable journalism. Overall, coverage of politics and science fares relatively well in building source credibility, whereas coverage of popular culture undermines credibility assessments. People find news sources that correct misinformation more credible when they cover a range of serious topics, but less credible when they cover lighter topics.