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bryce_kellogg

Bryce Kellogg

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Analysis of partisan bias in DMAC proposed Deschutes County Commissioner Districts
The Deschutes County Commission formed the District Mapping Advisory Committee (DMAC) to develop a plan for splitting the county into 5 commissioner districts. The resulting map called “Plan C” by the committee has been submitted to the county commission. County wide Democratic vote share in 2024 presidential election was 53.47%. The plan proposed by the DMAC favors Republicans in 3 of the 5 districts. This discrepancy shows that the proposed map favors Republican candidates when compared to at large elections. But is the map gerrymandered? The partisan bias could be the natural result of geography and voter distribution across the county rather than intentional crafting. To address this question we generate 20,000 district plans that follow requirements for population parity, continuity, and use of existing precinct boundaries. Simulating district plans allows for an apples to apples comparison with the DMAC’s proposed districts. We compare the Democratic vote share in the simulated districts to the DMAC proposed map. Partisan vote share is based on the results of the 2024 presidential election. This comparison shows the partisan bias of the committees proposed districts is not an inevitable result of county geography. The DMAC proposal packs Democratic voters into two districts, leaving three districts that favor Republican candidates.