As part of Ballotpedia's coverage of California Proposition 50, which proposed the state use a new district map to elect members of the U.S. House of Representatives from 2026 through 2030, I assessed how the new boundaries may impact the partisan representation of the state.

​

Methodology:

Proposed congressional district data was obtained from the California State Assembly. Precinct boundaries and 2024 election results were obtained from the California Statewide Database and Madera County GIS. Election results for existing districts were obtained from the California Secretary of State.

​

To estimate the political lean of each proposed congressional district, proposed boundaries were overlaid on precinct-level results from the 2024 presidential election. Because precinct and district boundaries do not align precisely, the area of each overlap was measured in square meters, and votes were proportionally allocated to districts based on the share of precinct area contained within them. The results were then aggregated at the congressional district level.