To build a more diverse STEM workforce, institutions seek to increase the representation of diverse groups in faculty and mentoring positions. The Learning Assistant (LA) near-peer student support program has the potential to bring diverse students into highly visible and impactful mentoring roles early in their college careers, benefiting both LAs and students in LA-supported courses. However, the demographic characteristics of potential students interested in the LA Program and the subsequent barriers to entry have yet to be investigated. This short-term longitudinal case study revealed that even though students from historically underserved groups (HUGs) started the semester equally as likely as non-HUGs to see themselves as future chemistry LAs, an inequity developed later in the semester. Similar trends were not detected based on students' gender or age group (traditional/nontraditional). Qualitative data indicated that regardless of demographic group, the most prominent barriers to students seeing themselves as future LAs include a lack of time and self-efficacy in chemistry content knowledge/social skills. The trends observed at this diverse metropolitan research institution indicate that further research is needed to find and lower barriers for students to have the opportunity to become LAs, especially those from HUGs.