Researcher positionality is widely accepted as a phenomenon to be understood and used to strengthen the qualitative research process. However, consideration of white researchers' positionality has largely centered on situations in which they are "outsider" researchers in spaces that do not reflect their own racial identities. To build knowledge about the effects of researcher whiteness upon research in white spaces with white participants, we analyze the first author's experiences amid qualitative research with white parents and youth within Chicago K-12 schools. Literature about researcher positionality and whiteness guides our analysis. We argue that white researchers' work with white participants reveals whiteness' mixed powers. Whiteness, if unchecked, can distort what white researchers learn, but can be a valuable research tool if acknowledged and fully interrogated throughout the inquiry process. From our findings, we draw implications for qualitative researchers, qualitative research methods instruction, and future "white-on-white" research.