I wish I was making this shit up.
Mathematics fields in the United States (US) were developed to preserve the elite status of White, upper-middle–class men (Castro, 2014; Leyva, 2017; McGee, 2016). Mainstream mathematics education plays a central role in this preservation and, consequently, in the marginalization of people of color (Battey & Leyva, 2016). Consistent racial ordering of mathematical achievement reifies a racialized hierarchy of mathematical ability, maintaining this status and effectively marginalizing Black, Indigenous, and Latinx students. We see this appear in White-normed measures such as the National Assessment of Educational Progress (NAEP) and college readiness exams (e.g., SAT) with little to no change across decades of school reform efforts. This hierarchy squarely places Black, Latinx, and Indigenous students on the bottom, and White and Asian students at the top (Deyhle & Swisher, 1997)
TLDR version: Non-whites/Asians don't perform well on math assessments. Therefore, racism.
One of the authors of the 126-page examination of racism in math is from Vandy. Her name is (I kid you not) Ebony McGee.