As California and Texas prepare to redraw their U.S. House district maps ahead of the 2026 midterm elections, the process is highlighting the influence redistricting can have on political power in Congress.
Texas lawmakers moved forward with new congressional boundaries after former President Donald Trump called on Republican-led states to redraw districts in ways that could favor Republican candidates, a practice known as partisan gerrymandering. In response, Democrats in California approved their own revised congressional map.
Historically, midterm elections tend to disadvantage the party holding the presidency. Trump has indicated he wants to avoid a repeat of the 2018 midterms when Republicans lost control of the House to Democrats during his first term, leading to significant challenges for his administration.
The Texas state Senate, controlled by Republicans, approved its new maps over objections from Democrats. The proposed districts now await approval from Republican Governor Greg Abbott, who has said he will sign them into law. These maps are expected to give Republicans an opportunity to gain up to five additional seats in Congress.
Meanwhile, California’s Legislature passed maps designed so Democrats could potentially pick up five seats. However, unlike Texas, these changes require voter approval in a special election scheduled for November.
Every ten years, data collected by the Census Bureau is used to apportion all 435 seats in the U.S. House of Representatives among the states based on population changes. States like California and Texas have more representatives due to their larger populations. Each state follows its own rules for drawing congressional districts; some states with small populations have only one representative covering the entire state.
The term “gerrymander” originated over two centuries ago in America as a way of describing political manipulation during legislative mapmaking. When one party controls both a state’s legislature and governor’s office—or holds enough legislative power to override vetoes—it can draw district lines that favor its interests. This often involves concentrating opposition voters into fewer districts or dispersing them across several districts to weaken their voting strength.
District boundaries are typically redrawn following each census but can be changed at other times if courts find existing lines unconstitutional or if state laws allow it. There is no federal restriction preventing states from redrawing districts mid-decade; however, while racial gerrymandering is prohibited by federal law, partisan gerrymandering remains permissible under current Supreme Court rulings (https://www.supremecourt.gov/opinions/18pdf/18-422_9ol1.pdf).
Doug Spencer, Rothgerber Jr. Chair in Constitutional Law at the University of Colorado, explained: “The laws about redistricting just say you have to redistrict after every census,” adding that some legislatures interpreted this flexibility as permission for more frequent changes: “And then some state legislatures got a little clever and said, ’Well it doesn’t say we can’t do it more.’”
Trump’s call for action led not only Texas but also Missouri and Indiana Republicans toward similar efforts; Ohio was already revising its map before Texas began its process (https://www.brennancenter.org/our-work/research-reports/redistricting-litigation-roundup). In contrast, California uses an independent commission system intended to keep politics out of map-drawing—a measure meant to avoid disputes like those unfolding elsewhere.
Democrats in Maryland and New York are considering revising their own maps as well; however, New York cannot implement any new district lines until 2028 without voter consent (https://nyassembly.gov/leg/?default_fld=&leg_video=&bn=A08341&term=0&Summary=Y&Actions=Y&Text=Y).
Democratic-controlled states more frequently use commissions or set limits on how districts are drawn compared with Republican-led states—giving GOP-controlled legislatures greater freedom for swift revisions (https://www.ncsl.org/elections-and-campaigns/redistricting-commissions-table).
“The laws about redistricting just say you have to redistrict after every census,” Doug Spencer said. “And then some state legislatures got a little clever and said, ’Well it doesn’t say we can’t do it more.’”
###
