When Bill Clinton won the presidency in 1992, about a fifth of California voters had used their vote-by-mail (or absentee) ballot to vote. That number has been increasing since then. The pandemic this year prompted California to mail all registered voters their ballot, driving the number to 87%. Here’s a caveat about where more voters used mailed ballots: counties are allowed to count mailed ballots that are dropped off at vote centers or drop boxes in this category. Our analysis here excludes three small counties that already exclusively voted by mail — Alpine, Sierra, and Plumas — as well as six counties that counted every ballot as vote by mail even if cast in person. Those counties include Lassen, Sutter, Mariposa, Stanislaus, Trinity, and Merced.
|Small counties||Medium-sized counties||Large counties|
|Mendocino County 99%||Butte County 96%||Santa Clara County 93%|