Voters changing party

Statewide, by month, from the State Board's monthly reports, January 2010 to September 2026.

Maryland's primaries are closed: a voter can take part only in the primary of the party they are registered with. Voter registration, party changes included, closes 21 days before an election, and voters who are not affiliated with a party may still join one until the day before early voting begins (State Board of Elections). The reports give the party a voter left, not the party they joined.

Around each primary

In 4 of the 9 primaries (June 2014, July 2022, May 2024, June 2026), the month of the primary had fewer party changes than any other reported month of that year. In 3 (September 2010, April 2012, April 2016) it had at least a quarter more than a typical month. The pattern is not the same every year.

Primary Month before Primary month Typical month Primary month vs typical Rank in year
2010-09-14 17,491 7,233 4,277 +69% 9 of 12
2012-04-03 6,505 7,770 5,809 +34% 9 of 12
2014-06-24 6,058 3,481 4,821 −28% 1 of 12
2016-04-26 28,960 19,463 14,207 +37% 9 of 12
2018-06-26 7,736 6,321 7,736 −18% 5 of 12
2020-06-02 10,285 8,378 12,180 −31% 3 of 12
2022-07-19 19,751 1,599 9,074 −82% 1 of 12
2024-05-14 15,407 3,708 14,662 −75% 1 of 12
2026-06-23 11,891 5,163 9,014 −43% 1 of 9

"Typical month" is the median of the year's other reported months. "Rank" is the primary month's place among the year's reported months, with 1 meaning the fewest changes. The 2026 figures cover only the 9 months reported so far.

By calendar year

YearVoters who changed party
2026 (9 months) 80,263
2025 89,752
2024 161,107
2023 58,309
2022 115,994
2021 72,323
2020 199,027
2019 82,503
2018 93,668
2017 50,057
2016 182,658
2015 63,712
2014 64,818
2013 51,811
2012 90,495
2011 25,025
2010 90,893

The rows are in registration_activity_all.csv, measure party_affiliation_changes_from. Primary and general election dates are entered by hand from the State Board's election archive.