Prior research has demonstrated a preference among partisans for like-minded news outlets, a key mechanism through which the media may be polarizing Americans. But in order for source reputations to cause widespread selective exposure, individuals must prioritize them above other competing attributes of news content. Evaluating the relative influence of various contributors to media choice is therefore critical. This study pits two such factors, source reputation and topic relevance, against one another in conjoint survey experiments offering randomly paired news items to partisans. Making a news source’s reputation politically unfriendly lowers the probability that an individual chooses an item, but this negative effect is often eclipsed by the positive effect of making a news topic relevant to the individual. In many popular modern news consumption environments, where consumers encounter a diverse mixture of sources and topics, the ability of source reputations to contribute to polarization via partisan selective exposure is limited.