939: Odds of a Dummymander

Breaking the gerrymander driving up the GOP's chances of keeping the House

Three months ago, betting markets gave Republicans a 15% chance of keeping control of the House after the midterms¹.

Today, it is 27%. The underdogs have nearly doubled their odds, to the point where there is a better chance the GOP will hold the House than a Major League Baseball at bat will yield a hit.

The Senate story is “the same, but different.” Different in that it is the Democrats, mired at 47 seats, who are the underdogs. The same in that the underdog is surging, jumping from 18% in March to as high as 33%.

What’s going on?

We have two optimistic hypotheses:

First, the betting markets are realizing what we’ve been pitching for four years: amid intense political polarization, voters are still volatile and the political chattering class is overly confident in its predictions. See: here, here, and here.

Second, candidates really matter!! A few good Senate candidates can juice the odds, and a full slate of strong House candidates - including in stretch districts - is needed to keep GOP odds lower in the lower chamber.

But here’s a problematic third factor contributing to higher GOP odds in the House: gerrymandering is driving up the GOP’s odds of keeping the House.

But they are also driving up the odds of a dummymander. And we need more groups focusing on the dummymanders.

Gerrymander

We are typically not “blame the gerrymander” people. After all, the biggest problem for Democrats is in the Senate, where district lines have been the same since 1959.

And the House is actually pretty fair!

As three top political scientists wrote months ago in The Washington Post:

Here’s another assumption punctured by the 2024 election: that gerrymandering and Democratic vote-clustering give Republicans a structural advantage in the battle for control of the House of Representatives.

For more than two decades, the House was consistently biased in Republicans’ favor. Votes cast for GOP candidates translated into congressional seats more efficiently than did votes for Democrats. In 2012, most dramatically, Republicans won a majority of more than 30 seats with a minority of the aggregate nationwide vote. Political observers debated whether this skew was “natural” — a by-product of the country’s political geography — or the result of Republican gerrymandering. But few doubted that the House was, in fact, tilted to the right.

Now, that fixture of American politics is gone. In the 2022 and 2024 elections, according to standard measures of partisan bias, the House exhibited no pro-Republican lean at all. Of course, Republicans won narrow majorities in 2022 and 2024. But they did so because they won narrow pluralities of the total House vote. For the first time in a generation, both Republicans’ control of the chamber and their slim governing margins accurately reflected voters’ preferences.

That said … the GOP is playing hardball to maintain these historically narrow House margins. And that means seeking advantages by operating between the decennial redistricting cycles.

Last week, Texas Governor Greg Abbott announced a special session for some congressional gerrymandering. Abbott is looking to shore up the GOP House majority after the drastic cuts to Medicaid in the “One Big Beautiful Bill”. According to the non-partisan Kaiser Family Foundation, 64% of adults have an unfavorable view of the OBBA, including a shocking two-thirds of Republicans who do not identify as “MAGA.” Other polls tell a similar story. In 2018, opposition to Trump’s attempts to repeal the ACA led to a blue wave. Republicans are desperately trying to avoid a similar fate today.

Which leads us to the Texas gerrymander. It’s not the first time Republicans in Texas have pulled a mid-decade gerrymander. In 2003, Tom DeLay orchestrated a successful gerrymander that wiped out federal House Democrats in the state. This time, election analysts estimate that Republicans could gain as many as 5 seats from the gerrymander.

In Ohio, Republicans are also redrawing districts, due to a unique law requiring a mid-decade re-draw because the initial map was passed without bipartisan support. Republicans are likely to target Marcy Kaptur and Emilia Sykes, both overperformers, to move a 10-5 map into a 12-3 map.

It’s awful, and frustrating, so what are Democrats to do?

Increase the odds of a “dummymander.”

Dummymandering

GOP efficiency in redistricting can yield unintended opportunities for Democrats. When parties go for a highly efficient gerrymander, they aim to create maps that favor their party by ~10 points, not 20 points. If you are winning by more than 15 points, you should move some of your voters into a nearby district that is more competitive. However, if a gerrymander makes too many districts just competitive enough, it can backfire and become a “dummymander.”

For instance, Republican Pete Sessions represented a district drawn to be R+13 in the 2012 election. In 2016, the partisan lean dropped to just R+10. In 2018, former NFL player Colin Allred defeated Sessions with a Wins Above Replacement (WAR) of 6.

Overperformance levels like those put up by Allred, Kristen McDonald Rivet, Jared Golden, and Marie Gluesenkamp Perez can turn efficient gerrymanders into dummymanders.

We need a whole bunch of people ready to make bets on potential dummymanders - even the type of long shot bet that scares off most interest groups and donor advisors. Here’s a recent post showing that attitude, from

Tony Vargas

at Square One Politics about their stretch bet this cycle:

At first glance, TX-31 should be completely out of reach for Democrats. Incumbent Republican John Carter has been in Congress for more than two decades, easily winning re-election in all but one race. Carter defeated his Democratic opponent last November by nearly 30 points; Trump won the district by 23 points.

TX-31 is by far the most Republican-leaning district on our list of 2026 targets. But here’s why we think it’s worth paying attention to.

The makeup of the district is shifting, with more and more people moving north from deep-blue Travis County, home to Austin. And while Kamala Harris underperformed Joe Biden’s 2020 showing, she outperformed Hillary Clinton by 7 points here – a remarkable performance made even more notable given Hillary outperformed Kamala statewide by 5 points in 2016. Even against strong headwinds, the district is changing in our favor.

Betting markets are in flux because voters are far more volatile than the political narrative suggests. When leaders like Tony, a former state Senator from Nebraska, lead organizations to make these sorts of bets we can turn GOP efficiency into opportunity.

With support, candidates can generate massive “wins above replacement” and break the models that assume standard political dynamics. After all, the last Texas gerrymander turned into a dummymander that yielded a six point WAR performance from Allred for Senate in 2024 - enough to make Texas a toss-up in a D+6 year, like 2026 could be.

If Democrats run these candidates everywhere, the gerrymanders won’t hold. And those dummymanders may even lead to more Senate candidates down the line.

Or more. 939 days until the next presidential primary.

PS to think about how YOU can help make a dummymander, check out Lakshya Jain’s presentation from WelcomeFest, where he identifies the stretch districts that Democrats should be competing in. And the refrain: learn from the people who did well in elections.

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1. April 11 odds on Kalshi