By Kenneth P. Miller and Quinten Carney | Inland Empire Economic Partnership
The United States has entered an unprecedented period of mid-decade partisan congressional redistricting, driven by President Donald Trump and rival states Texas and California. This high-stakes struggle could determine party control of the U.S. House of Representatives in next year’s midterm elections, thereby either sustaining or checking Trump’s power during his administration’s last two years. At the same time, the battle risks further dividing states along partisan lines and undermining California’s hard-won redistricting reforms.
States typically redraw congressional district lines only once per decade, after the decennial Census. But in a bid to preserve his party’s razor-thin House majority (currently 219-213), Trump urged Texas, the most populous Republican state, to redraw its congressional lines to maximize partisan advantage. Texas obliged, approving a Republican gerrymander aimed at increasing the party’s congressional seat margin in that state by five seats, from 25-13 to 30-8, in next year’s midterm elections.
California’s Democratic leaders quickly responded by proposing a counter-gerrymander designed to flip five of the state’s congressional seats to blue, thereby expanding Democratic domination of the state’s House delegation from 43-9 to 48-4.
In Texas, Gov. Greg Abbott and the GOP-controlled legislature had unchecked power to draw new congressional districts, but California Democrats must win voter approval for their counterpunch. California’s Constitution allows only one redistricting per decade and California voters have twice approved (in 2008 and 2010) state constitutional amendments to remove redistricting power from the Legislature and the governor and to give it to an Independent Citizens Redistricting Commission.
Last month, the California Legislature drafted a ballot measure, Proposition 50, that would authorize replacing the Independent Citizens Commission’s congressional districts with an explicitly partisan gerrymander for the next three election cycles. Gov. Gavin Newsom has called a special election on Nov. 4.
The special election will be the nation’s most consequential political contest this fall.
Across the country, Proposition 50 will be seen as a referendum on the president and his efforts to retain Republican control of Congress in 2026. It also presents a crucial test for Newsom, who has staked his political future (including his nascent campaign for the 2028 Democratic presidential nomination) on the fate of Proposition 50. At another level, the election will determine the depth of California’s commitment to political reform and independent, rather than partisan, redistricting.
How could Proposition 50 make such a big difference? How could redrawing district lines shift five California congressional seats from Republican to Democrat? Although line drawing cannot guarantee election outcomes, increasing polarization and sophisticated computer technology make it possible for partisan mapmakers to achieve their goals with great probability. A closer look at parts of Southern California shows how the scheme would work.
In general terms, the Democratic plan achieves its objectives by breaking up districts with small Republican majorities and packing as many Republican-aligned voters into a few districts, thereby “wasting” Republican votes. At the same time, the plan distributes Democratic-aligned voters efficiently, creating safe, but not excessive, majorities in as many districts as possible. (The same techniques apply, in reverse, in Texas.)
This strategy is clearly displayed in Southern California. The proposed Democratic map targets two of the region’s four Republican House members, Rep. Ken Calvert and Rep. Darrell Issa, for defeat.
Most notably, the plan would likely end Calvert’s long congressional career by eviscerating his 41st District in the Inland Empire. This district stretches across Riverside County from Corona, Menifee, and Murrieta to the Coachella Valley. The new map would eliminate the district in its current form and create a new, majority-minority, safely Democratic 41st District in Southeast Los Angeles County and Northern Orange County, centered in Whittier and Downey. The communities Calvert now represents would be split among several other districts.
The Democratic plan also takes aim at Issa, who represents the 48th District in inland San Diego County and southern Riverside County. The plan would remove that district’s Republican-aligned Eastern San Diego suburbs such as Santee and Lakeside, in exchange for more Democratic-leaning areas around San Marcos and Escondido. It also would expand the 48th District further into Riverside County to pick up some of the areas Calvert currently represents.
The proposed map would thus place Issa and Calvert in a new Democratic-leaning 48th District, forcing the two Republican incumbents to compete against each other if both seek to run again. Neither of them would be favored to win the district.
The plan would pack many Republican areas stripped away from Calvert and Issa into the GOP-aligned 40th District, thereby creating a Republican “vote sink.” Republican Rep. Young Kim would easily win reelection in the new 40th District, even as her party’s candidates lose in surrounding districts.
Meanwhile, the new map seeks to protect potentially vulnerable Democrats in the region. For example, in the Inland Empire, the map would shift Republican precincts out of districts represented by Democrat Congressmembers Mark Takano and Pete Aguilar and pack them into the safely Republican 23rd District, centered in the high desert and represented by Rep. Jay Obernolte.
Farther west, the new 35th District, represented by Democrat Congressmember Norma Torres, would move into Los Angeles County, and pick up the Democratic strongholds of Claremont and portions of Pomona.
These examples, matched in other parts of the state, show how a skilled partisan line-drawer can create a congressional delegation with 48 of 52 Democratic members (92%) in a state where Trump won 38% of the statewide vote in the last presidential election. This skew would match or exceed what Republicans were able to achieve in Texas.
More broadly, this trend toward seeking maximum partisan advantage, state-by-state, in drawing congressional districts is further polarizing the nation along red vs. blue state lines. Several other states, including Missouri, Florida, Indiana, and Maryland, are considering redrawing congressional districts this year. And the U.S. Supreme Court eliminated a potential check on this competition when it held in Rucho v. Common Cause (2016) that federal courts cannot review the constitutional validity of partisan gerrymanders.
Many California voters will surely conclude that resisting Trump and countering Texas justifies ditching the state’s Independent Redistricting Commission’s congressional districts and embracing partisan gerrymandering. They will conclude California should not unilaterally disarm in this national contest to game congressional elections. But others will hesitate, either because they oppose the Democratic plan or because they dislike partisan line drawing by either side and want to preserve the integrity of California’s independent redistricting system. Either way, the vote on Proposition 50 will have major consequences for California and the nation.
Kenneth P. Miller: Director, Rose Institute of State and Local Government, Professor, Department of Government, Claremont McKenna College, Inland Empire Economic Council; Quinten Carney: research analyst, Rose Institute of State and Local Government at Claremont McKenna College.
The Inland Empire Economic Partnership’s mission is to help create a regional voice for business and quality of life in Riverside and San Bernardino counties. Its membership includes organizations in the private and public sector.
