The Operational and Partisan Impact of California's Election Administration System
December 2025
by Keith Maben '28
This report aims to determine the effect of California’s universal vote-by-mail (VBM) system on ballot counting times and partisan outcomes in the state. The VBM system was designed to increase voter turnout and make voting as accessible as possible, but came with the drawback of potentially slowing down the vote-counting process. First, analysis of Unprocessed Ballot Report (UBRs) from all California counties was used to determine whether counties with longer usage of the universal VBM system counted their ballots more efficiently. Second, an analysis of vote-count snapshots for congressional elections was conducted to determine the partisan effects of late-arriving ballots. A clear “rollout effect” was found, and the longer a county used universal VBM, the more efficient it became at ballot processing. A notable partisan effect was found as well, as Democratic congressional candidates were found to have systematically benefited from late ballot arrival and ballot curing deadlines. While VBM efficiency is improving through institutional learning, there remain persistent regional inefficiencies that are a cause for public concern. Furthermore, the structural partisan advantage of ballot deadline laws remains a key factor in the national contest for control of Congress.