A recent Supreme Court decision has opened the door for more aggressive political map-drawing that could further reduce the already historically low number of competitive congressional races this fall.
The court’s Wednesday ruling comes during an unprecedented national battle over congressional redistricting and may herald a new phase of blatant partisan gerrymandering that creates even fewer contested elections, diminishing voter influence, according to political experts.
The scarcity of contested races means House control will probably be decided in November’s midterm elections by less than 10% of Americans, with winners in most districts virtually guaranteed before any votes are counted, a Reuters analysis revealed.
According to the analysis, just 32 of the House’s 435 seats are presently viewed as competitive. These districts received ratings as toss-ups or leaning Democratic or Republican from three prominent independent forecasters: Cook Political Report, the University of Virginia’s Crystal Ball and Inside Elections.
The remaining districts are essentially unwinnable for the opposing party. Cook rates 375 seats—over 85% of the House—as either “Solid Republican” or “Solid Democrat,” indicating analysts don’t anticipate serious challenges. Cook labels another 28 races as “likely” Republican or Democratic, meaning they’re currently non-competitive but could shift under different circumstances.
This election cycle features the smallest number of competitive House contests at this point since at least 2008, based on archived Cook ratings.
Democrats require only three additional seats to secure a House majority, granting them authority to obstruct President Donald Trump’s legislative priorities and launch investigations into his administration.
The diminishing House battleground stems from multiple causes, including heightened political polarization. However, the strategic use of congressional redistricting, or gerrymandering—which intensified after Trump began urging Republicans to create new maps last year—represents a crucial factor that will only accelerate following the Supreme Court’s decision, experts indicate.
“We are now in a cycle of gerrymandering wars,” stated Justin Levitt, a Loyola Law School professor who operates the All About Redistricting website. “What used to be a cold war has gotten very hot.”
The court weakened a federal Voting Rights Act provision that previously prevented state legislatures from eliminating districts with predominantly racial minority populations. Political analysts anticipate Republican-controlled states will target a dozen or more Democratic-held majority-Black and majority-Latino seats that formerly had stronger protections.
“I think it gets worse before it gets better,” Levitt commented. “And I think there’s plenty of room for it to get worse.”
The shortage of competitive districts can impact Congress significantly, explained Matthew Klein, a House analyst with Cook. When House candidates only need to attract their base supporters to win rather than moderates or opposing party members, they’re more inclined to embrace extreme positions instead of seeking middle ground.
“If you look at Congress and how it acted 20 years ago, 30 years ago, even farther back, you see a Congress that is both less acrimonious and also more productive,” he noted. “There used to be bills that passed with huge majorities on major issues. We just don’t really see that anymore.”
While gerrymandering has existed throughout American democracy, the practice has intensified recently as both legal and institutional safeguards have disappeared. In 2019, the Supreme Court determined that although partisan gerrymandering might be undemocratic, federal courts couldn’t regulate it.
Last year, Trump successfully convinced Texas Republicans to abandon their existing map and create a new one targeting five Democratic incumbents, sparking a nationwide competition that expanded to nearly a dozen additional states. This action destroyed the traditional practice of limiting most redistricting to each decade’s beginning, following completion of the U.S. Census population count.
Wednesday’s Supreme Court ruling has provided lawmakers even greater freedom to draw districts favoring their party. These developments have occurred alongside technological improvements, enabling mapmakers to identify Democratic and Republican voters down to individual census blocks.
“If there are no guardrails, there are no guardrails,” Levitt observed. “I think the constraint is now realpolitik and imagination, not, ‘We just don’t do that.’”
Gerrymandering isn’t solely responsible for the lack of competitive districts. Voters have become more geographically separated, with rural areas becoming more conservative while suburban regions shifted left.
Just as House members have grown more polarized, voters have followed suit. Split-ticket voting, where voters select candidates from different parties for various offices, was once relatively common but has largely disappeared.
In 2000, 86 House members were elected from districts that voted for the opposing party’s presidential candidate, according to research by Kyle Kondik, Crystal Ball’s managing editor. In 2024, that figure dropped to 16.
