In Tennessee’s 9th District, a single seat held by Democrats survived by just 2,500 votes on Friday after Republican mapmakers reshaped the territory into a stronghold Donald Trump had carried by 21 points two years prior.
The 2026 midterm elections tested the limits of partisan redistricting across the United States, revealing that carefully drawn political boundaries can backfire dramatically during wave elections. While Republican mapmakers engineered maps in states like Ohio and North Carolina to secure lopsided majorities, a national Democratic backlash upended those calculations. At the same time, defensive gerrymanders in Texas and Florida largely held firm against a rising tide.
Republican state legislatures in Ohio and North Carolina redrew their congressional maps in 2025 to increase their power in the U.S. House of Representatives. In Ohio, 12 of 15 targeted districts included a majority of voters who backed Trump in 2024. North Carolina pursued a similarly aggressive strategy, packing 11 out of 14 newly drawn seats with safe margins for the former president.
Instead of securing a permanent advantage, these overextended districts crumbled under the weight of the 2026 Democratic wave. Voters in seats Trump had carried by double digits defected to the opposition. In Ohio, a plan aimed at capturing a two-thirds majority netted Republicans less than half of that goal, aligning the delegation closer to the state’s popular vote share.
North Carolina proved to be an even sharper miscalculation. Republicans aimed to capture nearly two-thirds of the state’s congressional seats, but the party is now poised to hold less than a third.
Further south, Republican strategies yielded different results. Lawmakers in Texas and Florida targeted nine Democratic-held seats, along with a vulnerable district held by U.S. Rep. Shomari Figures in Alabama, by engineering boundaries that Trump had won by at least 9 percentage points in 2024.
Those specific flips stalled as the Democratic wave swept through the deep South. Yet, the broader maps in Texas and Florida were drawn so favorably for Republicans that their overall delegations remained identical to the previous Congress. Historic shifts among Hispanic voters who had previously supported Trump helped Democrats retain targeted marginal seats, but the baseline map architecture continues to insulate safe Republican districts from shifting tides.
Meanwhile, court interventions altered political boundaries elsewhere. In states like Missouri and Utah, courts struck down maps that would have locked in lopsided advantages, sparing Republicans from further dummymanders that could have cost them additional seats during the midterms. Similar proposals failed inside state legislatures in Indiana and South Carolina, leaving Democrats with a pair of seats in each state rather than facing total shutouts.
The 2026 cycle demonstrated that wave elections can easily overwhelm partisan mapmaking. Yet future contests may still vindicate the underlying math as national environments shift. Both parties now navigate the post-decision reality of Louisiana v. Callais, a Supreme Court ruling that lowers legal hurdles for racial redistricting.
