An unprecedented wave of mid-decade redistricting for the U.S. House of Representatives altered the electoral districts of about one-tenth of the population and significantly changed the composition of at least one-fifth of the districts, according to a new study.
A report by Protect Democracy indicates that 34.8 million people—approximately 1 in 10 Americans—now live in a district different from the one they were in during the 2024 election cycle. The study also estimates that about one-fifth of the population now lives in districts where more than a quarter of voters are “new” relative to the previous cycle.
According to the survey, the partisan battle over electoral maps, fueled last year by initiatives associated with President Donald Trump, led to broad reconfiguration across several states. The new lines are being drawn increasingly to favor partisan interests, at the expense of criteria such as geography and communities with common ties, fueling academic concerns about the impacts on democracy in a highly polarized political environment.
‘If this trend continues, it remains in doubt whether elected officials still represent their voters, or if voters are being ‘chosen’ by those who draw the maps to extract partisan advantage,’ said Ben Raderstorf of Protect Democracy and coauthor of the study.
The battle began when Trump urged the Texas Legislature, controlled by Republicans, to redraw the map to benefit the party. The move provoked a reaction in California, which approved changes by referendum to favor Democrats. Other states followed suit, and the report states that Republicans could gain as many as nine additional seats because of redistricting.
The study warns that these tactics erode trust in elections, shield incumbents from shifts in public opinion, and hinder political organization, which could deepen polarization. It also notes the risk of a ‘vicious cycle’ in which both parties adopt increasingly aggressive and frequent measures to avoid losing ground.
In states like Missouri, redistricting created confusion about which district a voter is in and which candidates will appear on the November ballot. After conflicting rulings in lower courts, the Supreme Court blocked last week new districts in the state backed by Trump that had been used in the primaries, forcing a return to the previous map for the general election.
The report advocates reforms to reduce incentives for electoral manipulation, such as proportional representation or a formal truce between parties to implement nonpartisan maps. Nine states already use independent commissions, but there are limits: California, for example, suspended its model by referendum last year, in response to Texas’s movement.
