A Detailed Analysis of Missouri’s New Congressional Map
September 29, 2025 · 9:41 AM EDT
The unprecedented redistricting arms race of 2025 continues apace. After Texas Republicans redrew their state’s congressional map with the goal of flipping from three to five House seats, California Democrats voted to place their own new congressional map before voters this November that would do the same thing. Now, Missouri Republicans are getting in on the act: This past weekend, Republican Gov. Mike Kehoe signed into law a new map for the Show Me State that turns Missouri’s 5th Congressional District from a deep-blue seat to a dark-red one. As a result, Inside Elections is changing our rating for the seat from Solid Democratic to Solid Republican.
At least for now. There is some reason to believe it won’t be in effect by the time of the 2026 midterms. Multiple lawsuits have already been filed against the map, and voters may have the chance to veto it in a referendum next year. For now, though, here is a detailed analysis of the new plan.
Overview
Missouri’s congressional map was already pretty good for Republicans — and bad if you like competitive elections. According to Inside Elections’ Baseline, our measure of the baseline partisanship of states and congressional districts, the old map had six seats that were R+10 or redder and two seats that were D+10 or bluer — and no seats in the competitive zone in between. This resulted in a congressional delegation that has consisted of six Republicans and two Democrats since 2013.
The new map, however, features seven districts with a Baseline of R+10 or redder and leaves just one seat that is D+10 or bluer. There are still no seats between D+10 and R+10.
The efficiency gap statistic helps quantify how much better the new map is for Republicans than the old one. Efficiency gap is a measure of how many of one party’s votes are “wasted” versus the other’s. (For these purposes, any vote cast for the losing party or cast for the winning party after it already won a majority is considered wasted.) An ideal efficiency gap is 0, meaning that each party has the same number of wasted votes. Missouri’s old congressional map had an efficiency gap of R+10, meaning Republicans wasted 10 percentage points fewer votes than Democrats did. The new map has an efficiency gap of R+21.
District By District
The specific way that the new map squeezes an extra Republican seat out of Missouri is by breaking up the Kansas City area. Previously, most of this heavily Democratic region was covered by one very compact seat, Rep. Emanuel Cleaver’s 5th District. Under the new map, however, it is split among three districts — the 4th, 5th, and 6th — that also stretch well into rural central Missouri.
That means the 5th District now includes solidly Republican counties such as Lafayette, Johnson, and Pettis (currently represented by Republican Rep. Mark Alford). That’s enough to take its Baseline all the way from D+23 to R+17, all but dooming Cleaver’s re-election bid. (He says he will run again no matter what happens with the maps.)
To balance things out, Alford’s 4th District now includes a thin sliver of Kansas City between the Kansas-Missouri border and Troost Avenue — historically the dividing line between the city’s white and Black neighborhoods. (As a result, the map has come under fire for being racially insensitive as well as politically unfair.) As a result, its Baseline goes from R+41 to R+20 — less red, but still safely Republican.
Meanwhile, GOP Rep. Sam Graves’ 6th District, previously an R+38 district spanning northern Missouri, now takes in more of Kansas City’s northern suburbs, including North Kansas City and Gladstone. It, too, is still safely Republican at R+26.
Those aren’t the only changes the new map makes, though. Republican Rep. Ann Wagner’s 2nd District, based in the St. Louis suburbs, now extends further into conservative southern Missouri. That nudges its Baseline from R+11 to R+14 — a small shift, but one that could insulate Wagner if a blue wave develops in 2026 (or a future election).
As a domino effect from the above changes, GOP Rep. Bob Onder’s 3rd District also looks fairly different under the new map; it’s now a more compact collection of counties between St. Charles, Columbia, and Hannibal. However, its partisanship is little changed; at R+20, it remains a solidly Republican seat. Finally, the 1st District changes little under the new plan, and the southern-Missouri-based 7th and 8th districts are exactly the same.
What’s Next
As mentioned, however, this map faces multiple hurdles that could prevent it from actually being used in next year’s elections. The most straightforward is that it could be blocked in court; two separate lawsuits have already been filed arguing that the Missouri Constitution does not allow mid-decade redistricting, and a third alleges that the special session at which the map was passed was called illegally. St. Louis Magazine also reported on a potential error in the map, where a block in Kansas City may have been assigned to two districts at the same time. One of the lawsuits mentions this as a reason to strike down the map.
However, a likelier path to blocking the map — and certainly the one that opponents have the most control over — might be to put it before voters in a veto referendum election. Missouri is one of 23 states that allows ordinary citizens to attempt to repeal a law passed by the legislature by collecting enough signatures to put it on the ballot in a future election; if a majority of voters don’t vote for it at that point, it is stricken from the books. This process has a long and successful history in Missouri; such a referendum has qualified for the ballot 27 times, and voters vetoed the law in question 25 of those times. (Most recently, voters in 2018 rejected a law passed by the legislature to make Missouri a “right-to-work” state, 67 percent to 33 percent.)
Here in 2025, a coalition of liberal groups calling itself People NOT Politicians has already started collecting signatures to force a public vote on the new congressional map. They have until December 11 (90 days after the end of the legislative session that passed the law) to collect a number of signatures greater than or equal to 5 percent of the 2024 gubernatorial vote in six of the state’s eight congressional districts, which amounts to at least 106,384 signatures. If they are successful, a referendum over the map would appear on the November 2026 ballot — and, crucially, the map would be put on pause until the referendum takes place. Effectively, that means Democrats can block the map from getting used in the 2026 elections just by collecting enough signatures.
If that happens, the legislature would be allowed to move up the date of the referendum so that the map’s fate would be decided sooner — in other words, so that it could be used in 2026 if voters give it their OK. That could set up two high-stakes referenda — Missouri’s and California’s — over redistricting right on each other’s heels in late 2025 or early 2026.
It’s too early to say how Missourians might vote on such a referendum. A Change Research survey sponsored by the Democratic Congressional Campaign Committee recently found that registered voters in Missouri opposed efforts to redraw Missouri’s congressional map 44 percent to 37 percent, with 19 percent undecided. Of course, this was an internal Democratic poll and did not specifically ask about a potential ballot measure on the topic, so it should be taken with a big grain of salt. One thing that is for certain, however, is that such a referendum would be fiercely fought over, as it would essentially determine, months in advance, control of Missouri’s 5th District in 2026.