99chambers

U.S. House seat · current lines

Missouri's 3rd District

A district of about 783,000 people, 36% of adults with a bachelor's degree. It votes R+27.1 relative to the nation for president.

Robert F. Onder, Jr. (R) · since Jan 3, 2025Next election Nov 7, 2028The 2026 race →
MO-3

Source: 2026 results: civicAPI; boundaries: Census Bureau TIGER/LineUpdated Nov 7, 2026, 3:01 PM ET

Where it sits among all 435 seats

Every U.S. House seat by partisan lean, from most Democratic to most Republican. Lean is the seat's presidential vote on current lines, relative to the nation.

R+27.1356th most
Democratic
Most DemocraticMost Republican218th seat · the majority line152MO-36478

Labels below the bar mark 7 other seats in Missouri.

Source: 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET

Every race on these lines

Results recomputed from precinct returns as if today's boundaries had always existed, so years compare like for like.

202220242026
U.S. HouseR+30.2R+26.0R+8.5

Outlined: the race for this seat itselfBlank: no race that year

Source: 99chambers results archive: precinct results allocated to current lines; 2026: civicAPIUpdated Nov 7, 2026, 3:01 PM ET

Who lives here, compared

Grey bars show the spread of all 435 seats. Small marks are other seats in Missouri. The black marker is MO-3.

Adults with a bachelor's degree36% 59th pct · 3rd of 8 in MO

Higher than 59% of seats.

White adults without a degree56% 85th pct · 5th of 8 in MO

Higher than 85% of seats.

Hispanic residents4% 7th pct · 6th of 8 in MO

Lower than 93% of seats.

Black residents5% 35th pct · 3rd of 8 in MO

Lower than 65% of seats.

Asian residents2% 32nd pct · 3rd of 8 in MO

Lower than 68% of seats.

People per square mile102 25th pct · 5th of 8 in MO

Less dense than 75% of seats.

Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current linesUpdated Oct 13, 2026, 5:06 AM ET

Seats most like this one

Nearest seats on demographics, density and lean.

IN-4
32% college gradsR+30.0Held ROH-12
33% college gradsR+30.1Held RTN-6
34% college gradsR+25.7Held RIL-16
31% college gradsR+22.4Held R

Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current lines; 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET

Who has held it

  1. Bob Onder (R)
    2025– · Won 2024 by 26.0, 2026 by 8.5
  2. Blaine Luetkemeyer (R)
    2023–2025 · Won 2022 by 30.2

Source: Past results: 99chambers results archive (MEDSL, Klarner, state election offices)