Redistricting battles heating up across US

Editor’s note: “Behind the News” is the product of Sun staff assisted by the Sun’s AI lab, which includes a variety of tools such as Anthropic’s Claude, Perplexity AI, Google Gemini and ChatGPT.

Though the midterm elections are still a year out, the battle for U.S. House control has already begun in California.

On Monday, California voters started weighing in on a significant redistricting initiative that could create up to five additional congressional seats likely to favor Democrats — potentially counterbalancing redistricting efforts in Texas and other states aimed at helping Republicans ahead of the 2026 elections.

The simple yes-or-no ballot question, consisting of just 70 words, carries enormous implications: It may decide which party controls the narrowly divided House and whether Democrats can limit President Donald Trump’s agenda during the latter half of his presidency on key issues like immigration and reproductive rights.

Midterms to determine who will control House

Republicans hold a slim majority in the House with 219 seats, Democrats and independents hold 213, and there are three vacancies. To flip control in 2026, Democrats would need to gain at least four seats (from 213 to 217 out of 435, assuming the vacancies are filled).

Understanding redistricting

Redistricting is the process of redrawing the boundaries of congressional districts to account for population changes and ensure roughly equal populations. While it typically happens every 10 years after the U.S. Census, changes are more frequent in some states. States can draw districts via independent commissions or legislatures, which can lead to partisan advantages — a practice called gerrymandering.

What is happening in California

Proposition 50 asks voters if they want to override the current independent commission’s congressional map and approve new lines drawn by the Democratic-controlled Legislature [1]. The new map could add as many as five Democrat-favored seats starting with the 2026 election, increasing their expected seats from 43 to 48 out of California’s 52 districts [1, 2].

This change is a response to Texas Republicans redrawing their map mid-
decade in hopes of adding five seats for their party. A federal court panel is reviewing whether the Texas map can be used [2, 3].

National stakes

California and Texas, the two most populous states, are in a political tug-of-war, each seeking maps that maximize their party’s seats [2, 3]. This conflict may prompt similar battles in other states, affecting the delicate balance of power in Washington, D.C. Millions are being spent by both parties on ads to influence the vote, as control of the House hinges on just a few seats [1, 4].

Record-breaking campaign spending

The campaigns for and against Proposition 50 have spent over $215 million combined, making this one of the most expensive ballot measure fights in state history [5, 6]. Supporters of the proposition, led by California Gov. Gavin Newsom, have raised more than $138 million, while opponents have amassed roughly $77 million [5].

Over $100 million was raised in September [7]. The “Yes” campaign’s big donors include the House Majority PAC ($10 million), George Soros’ Fund for Policy Reform ($10 million), MoveOn.org ($6.9 million) and major teachers’ unions [5, 7]. The “No” campaign is funded in large part by the Congressional Leadership Fund ($42 million) and Charles Munger Jr. ($33 million) [5, 7].

Advertising investment

Supporters have invested heavily in advertising, spending $18 million on TV ads and $7 million on digital advertising, for over $25 million in total ad spending [8]. The supporters’ messaging centers on both anti-Trump sentiment and turnout among key demographics [8].

Opponents have spent nearly $27 million, predominantly on TV advertising that emphasizes the preservation of the independent commission and democratic values [7, 8].

This massive ad spending illustrates the critical national stakes: flipping up to five seats could change control of the U.S. House, making California’s redistricting a central battleground for both parties [8]. Campaign investment at these levels demonstrates that both national parties view redistricting fights not as local matters, but as crucial battlegrounds in the broader national struggle for congressional control [6].

The voter landscape

California’s voter registration landscape is heavily tilted toward the Democratic Party, with nearly 45% of registered voters identifying as Democrats as of 2025. The Republican Party trails significantly, with about 25% of registered voters, and independents make up roughly 22-23%. California has over 22.9 million registered voters [9].

Despite this Democratic advantage, voters are described as being “grumpy” and holding mixed opinions of partisan politics, which could add unpredictability to ballot measures like Proposition 50 [10]. The combination of a large Democratic registration advantage and a nationally “grumpy” voter mood suggests that support for Proposition 50 could be unpredictable, regardless of the clear partisan registration advantage [10].

Impact on rural and conservative areas

The redrawing of maps under Proposition 50 has raised concerns that some of the new districts could dilute the voice of rural and conservative-leaning areas, potentially weakening Republican influence in those regions [1]. Some newly proposed districts would slice across the state in ways that unite distant, ideologically different communities. For example, one district would combine Northern California’s rural, conservative areas with Marin County, a liberal coastal stronghold north of San Francisco [1].

John Chandler, a Central Valley farmer, expressed fears that combining rural farming communities with large cities in the new maps would cause them to “lose our voice” and harm their representation [11].

Other districts would remain largely unchanged or receive only minor adjustments, mainly affecting Republican incumbents’ districts such as those held by Reps. Ken Calvert, Doug LaMalfa, Kevin Kiley, David Valadao and Darrell Issa. These changes are designed to convert some Republican-held districts into more competitive or Democratic-leaning seats, thus reducing Republican representation in California’s congressional delegation from nine seats to potentially around four [1].

Yes, several states besides California and Texas are actively planning or considering redistricting as of October 2025, often in response to political pressure or court rulings.[12][13][14][5][16]

Other states actively pursuing redistricting

• Utah: The Legislature was meeting in special session Monday to vote on a new congressional map after a court ordered a redraw.[13][17][18]

• Missouri: The governor has signed an updated U.S. House map into law, aiming to increase Republican representation. The changes are facing legal challenges and potential referendum efforts.[13][19]

• Ohio: State law requires new districts before the 2026 midterms because the last map lacked bipartisan support. Republicans are expected to push for changes that could boost their House seat count.[13][14][16]

• Indiana: Discussions between state and national Republican leaders are ongoing, with a redistricting session likely later this year to potentially alter the map and target Democratic seats.[13][15][16][19]

• Kansas: Lawmakers are finalizing details for a possible special redistricting session in November, with the focus on altering a suburban Kansas City seat.[13]

• Florida: Republican leaders in the Legislature are considering a new congressional map, with support from Gov. Ron DeSantis for mid-decade redistricting.[13][15][16][19]

• Louisiana: Lawmakers are prepared to reconvene quickly for a special session depending on the outcome of a U.S. Supreme Court case concerning the congressional map.[13]

• Maryland: Democratic leaders have introduced legislation to pursue redistricting, citing opportunities to target Republican seats if other states proceed first.[13][15][16][19]

• New York and Illinois: Democratic governors have publicly floated mid-
decade redistricting efforts, though legal and constitutional barriers mean formal plans are less advanced compared with other states.[15][16]

Redistricting activity is spreading well beyond California and Texas, including a mix of red and blue states and remains subject to ongoing legislative battles, legal challenges and court rulings.[13][14][15][16][19]