Transformative changes in urban economies are raising vital questions about minority representation. Given that cities are sites of political power for communities of color, gentrification and the housing affordability crisis threaten to deteriorate decades of progress. This article considers the impact of these economic and demographic shifts on minority candidate supply and success. Collecting data on 166 city councils across several decades, we find that White population growth is associated with reductions in local political power for Black and Latino councilors. We also observe modest evidence that local economic improvements may not have deleterious effects on the diversity of city councils. We probe these findings using data on local elections, as well as over 380,000 tweets from city councilors, and uncover evidence of a candidate supply mechanism in the case of “racial gentrification” and a credit-claiming mechanism in the case of “economic gentrification.” We conclude by discussing the political implications of the cross-cutting effects we observe.