Consideration of socioscientific issues (SSIs) promotes the development of moral and sociocultural perspectives that encourage a rich understanding of the nature of science. The use of moral reasoning to approach SSIs is known to influence how students justify arguments and persuade others; less is known about how student moral reasoning is influenced by both content knowledge and demographic identities. We performed an exploratory study to investigate how students use moral reasoning when considering an SSI about the use of CRISPR/Cas9 technology for nonmedical enhancement in humans. Using content analysis, we examined written responses from 279 undergraduate students from three content knowledge levels and a variety of demographic populations (socioeconomic, gender, and first‐generation status). We identified instances of consequence and principle‐based moral reasoning and categorized commonly employed moral considerations under these broad themes. Students opposed nonmedical enhancement with CRISPR/Cas9 technology and perceived it as fraught with moral controversy primarily related to eugenics, equity, diversity, risk, and the authority of nature. Content knowledge level, gender, socioeconomic status, and first‐generation status influenced which moral considerations were employed by students and these carried interaction effects that indicate complex relationships between content knowledge level and demographic variables. We suggest more explicit instruction about complex societal issues linked to the history of science and genetic engineering, such as eugenics and inequity, and further investigation of moral perspectives for students from lower socioeconomic backgrounds and underrepresented groups so that these perspectives can be integrated into curricula to foster diverse classroom environments.