Bethany
E Mann
Bethany E. Mann is the 2026 Democratic nominee challenging Republican incumbent Bob Onder in Missouri's 3rd Congressional District.
- sources
- 11
- positions
- 9
- endorsements
- 5
Background
Bethany E. Mann is the 2026 Democratic nominee for Missouri's 3rd Congressional District, challenging Republican incumbent Bob Onder in the November general election. She has run for the same seat previously, including in 2022 and 2024, but has not held elected office. 1818
Mann describes herself as an environmental chemist and technology specialist. Her campaign biography states she began her career as an intern with the Environmental Protection Agency and later worked with laboratories serving agriculture, food and beverage, energy, and other industries, helping farmers test crops and communities test for environmental contaminants. 12
She holds a Bachelor of Science in Chemistry from the University of Illinois Springfield. She grew up in Foristell, Missouri, and the campaign says she now lives in St. Peters. 1
Mann won the Democratic primary on August 4, 2026, and faces Bob Onder, the Republican primary winner, in the general election. Columbia-area voters were redrawn into the 3rd Congressional District following recent redistricting. 8911
At a glance
- Party
- Democratic
- Running for
- U.S. House · District 3, Missouri
- Election
- Nov 3, 2026
- Current office
- Democratic nominee for Missouri's 3rd Congressional District (2026)
- Website
- bethanymann.com(opens in a new tab)
Where they stand
Each position links to the page it was drawn from. Quotes are verbatim.
Timeline
- Oct 7endorsementU.S. Chamber of Commerce endorses Mann's opponent Bob Onder for Missouri's 3rd District
The U.S. Chamber of Commerce announced its endorsement of incumbent Republican Bob Onder, not Mann, for the Missouri 3rd Congressional District general election.
U.S. Chamber Endorses Rep. Bob Onder for Missouri's ... · Oct 7, 2026 (opens in a new tab) - Sep 29newsMann reiterates voting-rights platform in press release following map ruling
Mann said she would work to pass the John Lewis Voting Rights Advancement Act and oppose gerrymandering, prison gerrymandering, and voter suppression. Coverage also confirmed the race is a 2024 rematch; Onder received 61.3% and Mann 35.3% in that prior contest.
Familiar faces await Cole County voters after congressional map change · Sep 29, 2026 (opens in a new tab) - Sep 25newsU.S. Supreme Court leaves 2022 map in place; Mann–Onder–Higgins race confirmed for November
The U.S. Supreme Court stayed a lower-court order requiring the 2025 map. The November District 3 race would proceed under older boundaries, with Mann facing Onder and Libertarian Jim Higgins.
Supreme Court orders usage of 2022 map in November election · Sep 26, 2026 (opens in a new tab) - Sep 25newsMann criticizes Onder over map fight, calls on voters to check registration
In a statement carried by First Alert 4, Mann criticized Onder's role in seeking the revised map and urged voters to check their registration and make a voting plan.
Local officials react to Supreme Court decision on Mo. ... · Sep 25, 2026 (opens in a new tab) - Sep 16newsMap uncertainty reported as a campaign complication for Mann and other Democrats
The Atlantic reported that Mann had been campaigning under both old and new district boundaries while the map dispute remained unresolved, requiring additional organizing, manpower, and money.
The Rules for This Election Keep Changing · Sep 16, 2026 (opens in a new tab) - Sep 3newsMissouri Supreme Court orders 2022 congressional map used, affecting District 3 race
The Missouri Supreme Court ruled the 2025 map could not take effect before a voter referendum, setting off further litigation over which map would govern the general election including the Mann–Onder race.
Familiar faces await Cole County voters after congressional map change · Sep 29, 2026 (opens in a new tab) - Aug 4newsBethany Mann wins Democratic primary for Missouri's 3rd District
Mann won the Democratic nomination, advancing from the primary with about two-thirds of her party's vote. She and incumbent Republican Bob Onder each advanced without strong opposition.
Familiar faces await Cole County voters after congressional map change · Sep 29, 2026 (opens in a new tab)
Endorsements
- Abortion Action Missouri PAC organizationListed under the organization's 2026 endorsements page under U.S. House (Cd-3). abortionactionmissouri.org
- Missouri Equity Education Partnership organizationListed on Mann campaign endorsement page. bethanymannforcongress.com
- American Youth 4 Climate Action & Sustainability organizationListed on Mann campaign endorsement page. bethanymannforcongress.com
- United Auto Workers (UAW) unionListed on Mann campaign endorsement page. bethanymannforcongress.com
- Elect Good People organizationListed on Mann campaign endorsement page. bethanymannforcongress.com
Campaign finance
Totals filed with the Federal Election Commission for the 2026 election cycle.
- Raised
- $43K
- Spent
- $45K
- Cash on hand
- $2,776
As of Jul 15, 2026. Filings are periodic, so recent money may not be included yet. ↳ FEC record H2MO03167(opens in a new tab)
Sources 11
- [1] U.S. Chamber Endorses Rep. Bob Onder for Missouri's ...(opens in a new tab) Oct 7, 2026
- [2] Endorsements(opens in a new tab) Oct 3, 2026
- [3] Platform | Bethany Mann for Missouri(opens in a new tab) Oct 3, 2026
- [4] Familiar faces await Cole County voters after congressional map change(opens in a new tab) Sep 29, 2026
- [5] Supreme Court orders usage of 2022 map in November election(opens in a new tab) Sep 26, 2026
- [6] Local officials react to Supreme Court decision on Mo. ...(opens in a new tab) Sep 25, 2026
- [7] The Rules for This Election Keep Changing(opens in a new tab) Sep 16, 2026
- [8] Endorsements | Trusted Supporters of Abortion Action ...(opens in a new tab) Aug 28, 2026
- [9] Missouri Third Congressional District candidate interview(opens in a new tab) Jul 24, 2026
- [10] Missouri Democrat Bethany Mann doesn't like Trump tariff plan(opens in a new tab) Oct 31, 2024
- [11] Bethany Mann, candidate for Missouri's Third ...(opens in a new tab) Sep 18, 2024