Who's running in Missouri's 3rd congressional district
3 candidates are on the ballot. Below is what each one says they stand for, what they have actually done in office or in public life, and the arguments published for and against them — each quoted from a named source rather than summarised by us.
3 candidates · ballot order · Bob Onder currently holds this seat
Medium confidenceMedium confidenceThe candidate's stated positions and basic record are documented, but coverage is thin — often little independent reporting, or criticism from only one side.What would raise it: More independent reporting, a documented voting record, or published criticism from a named opponent would raise this.
What they say they stand for
Their own words. Claims, not verified facts.
Fighting illegal immigration.
Lowering taxes.
Protecting Second Amendment rights.
School choice.
Opposing what he calls the 'woke agenda'.
Securing elections.
What they’ve actually done
Documented record from official sources.
US Representative for Missouri's 3rd District since January 2025.
Physician specialising in allergy and asthma care; attorney.
Won the August 4, 2026 Republican primary with 66.3% against John G. Fraser.
Endorsed by President Trump and Sen. Ted Cruz.
Did not respond to ABC 17 News's repeated interview requests before the primary.
Arguments in favor
His priorities — fighting illegal immigration, lowering taxes, protecting Second Amendment rights, school choice, opposing the 'woke agenda' and securing elections — reflect the district's values, and he has the backing of President Trump and Sen. Ted Cruz.
— Bob Onder campaign, reported by ABC 17 News
Arguments against
'When you look at his voting record, he does not have Missouri's interests in mind': he wrote legislation to cut landing fees for 'his hobby airline buddies' and to rename the Kennedy Center while tariffs hurt farmers, and twice voted against releasing the Epstein files until given permission.
— John G. Fraser, Republican primary opponent, to ABC 17 News
He offered up the congressional map to Trump that started Missouri's gerrymandering fight, and serves corporate interests instead of constituents.
— Bethany Mann, Democratic opponent, to ABC 17 News
What we couldn’t verify
No DCCC material naming Onder in 2026 could be found.
Onder's campaign website could not be located.
Whether Onder will debate Mann had not been reported.
Lowering costs for working families through stronger labour protections.
Increased investment in public education.
Expanding access to health care.
An independent AI commission to set guardrails for data centre and infrastructure development, with community buy-in.
Releasing the Epstein files and holding those in power accountable.
What they’ve actually done
Documented record from official sources.
Environmental and water chemist.
Democratic nominee for Missouri's 3rd District in 2022 and 2024.
Won the August 4, 2026 Democratic primary with 69.1% over Tommy Holstein.
Has not held elected office.
Arguments in favor
As a water quality expert she is invited into communities across party lines to explain the impact of proposed data centres, and 'families want a strong economy that works for everybody and not just the wealthy few'.
— Bethany Mann, to ABC 17 News
Arguments against
The district has been held by Republicans since 2013, Onder beat her in 2024, and both Democratic candidates face 'an uphill battle' in the district.
— ABC 17 News reporting; 2024 election results
What we couldn’t verify
No published criticism of Mann by name could be found — not from Onder's campaign, the NRCC, or mid-Missouri coverage.
Her fundraising totals and campaign website were not found.
Her strategy assumed the 2025 map diluted Onder's base; the general election will instead use the 2022 map, which KCUR reports is more Republican-leaning here.
Positions and criticism are quoted from the named sources, not our assessments. This is built to help you start getting informed — confirm the official candidate list with your election authority before you vote.
Missouri held its primaries on August 4, 2026 under the 2025 congressional map. On September 3 the Missouri Supreme Court suspended that map pending the November Proposition A referendum and ordered the general election held on the 2022 map with the nominees already chosen; the US Supreme Court stayed a conflicting federal order on September 10, and the Secretary of State directed use of the 2022 lines. An Eighth Circuit appeal is set for argument September 17, so lines could still change. Three candidates are certified, in the Secretary of State's August 25, 2026 order: Republican incumbent Bob Onder, who beat John G. Fraser 66.3% to 33.7%; Democrat Bethany Mann, the 2022 and 2024 nominee, who won her primary with 69.1%; and Libertarian Jim Higgins. KCUR reports the 2022 version of this district, which includes parts of Jefferson and St. Charles counties, leans more Republican than the 2025 version. The district has been held by Republicans since 2013, and forecasters rate it safe Republican.
This is one contest on a longer ballot
A Missouri ballot also carries state legislative districts, county offices, judicial seats and often local questions — and which of them you vote on is decided by your street address, not your city or ZIP code.