Which US states have the highest percentage of registered Democrats versus Republicans in 2025?
Executive summary
Registered-party strength in 2025 looks different depending on the measure: by raw voter-registration majorities and pluralities, Democrats hold the edge in places like the District of Columbia, Maryland, and the U.S. Virgin Islands, while Republicans command outright majorities in Idaho, Oklahoma, South Dakota, Utah and Wyoming; national aggregates that do exist show Democrats with more registered voters overall but a narrowing gap and uneven state reporting complicates a definitive ranking [1] [2] [3].
1. What the user is asking — registration share versus voting lean
The question targets “percentage of registered Democrats versus Republicans in 2025,” which is a request about party-registration shares rather than election outcomes; registration data are published by only a subset of states and territories, so the best available statements are: where Democrats form a majority or plurality of registrants, where Republicans form a majority or plurality, and national tallies from aggregators — all of which must be read alongside alternative partisan measures such as the Cook Partisan Voting Index (PVI) that reflect vote behavior rather than registration [1] [4].
2. The clearest headline: states and territories where Democrats are largest or a majority
Among reporting jurisdictions in 2025, Democrats comprised a majority of registered voters in the District of Columbia, Maryland, and the U.S. Virgin Islands, and were the largest single registration group (the plurality) in eight additional jurisdictions — Ballotpedia’s compilation is the primary source for these counts and maps of reporting states [1].
3. The Republican high-water marks: states with Republican majorities
Ballotpedia reports that five places — Idaho, Oklahoma, South Dakota, Utah and Wyoming — had Republican majorities among registered voters in 2025, and Republicans were the largest registration group in seven other reporting jurisdictions; statewide registration in these places shows the strongest Republican registration concentrations in the Mountain and Plains states [1].
4. Notable specific figures and alternative measures
For context, California contained the largest number of registered Democrats — over ten million — an indicator of scale rather than percentage, while Wyoming is repeatedly identified as the state with the highest percentage of registered Republicans (reported in some outlets as “over 80%”), illustrating the difference between absolute counts and percentage concentration [3]. Analysts also point out that the Cook PVI ranks Vermont as the most Democratic state by recent presidential vote patterns (D+16), which is a different, election-performance-based metric rather than registration [4] [5].
5. National picture and shifting balance
Aggregated reporting across the states that publish party registration shows Democrats ahead in total registered numbers — Ballotpedia’s 2025 compilation lists about 44.9 million registered Democrats versus roughly 38.0 million registered Republicans among reporting jurisdictions — but that edge has been narrowing and reporting coverage is incomplete: only about 30 states (plus DC and some territories) regularly publish partisan registration tallies [2] [1]. Independent and no-party registrations have grown, and organizations such as Pew and other analysts note a near-even partisan identification nationally in 2025 when measured by surveys, signaling a more fluid partisan affiliation environment beyond formal registration rolls [6].
6. Caveats, competing explanations and data limits
Two important caveats: first, many states do not require or publicly report party affiliation consistently, so any “top state” lists reflect the subset that does publish data and can miss large states that don’t report; second, registration does not always equal vote behavior — voters’ registration labels can lag realignment or reflect local primary rules and historical “ancestral” party attachments, meaning measures like PVI and turnout analyses can tell different stories than raw registration [1] [4] [7].