A long-standing debate weighs the roles of gerrymandering and residential sorting
The number of competitive U.S. House districts fell from 45 to 37 over the past year, and the Associated Press reported that the decline accelerated after Republican President Donald Trump sparked a partisan redistricting battle. The Associated Press summarized the change this way: “Voters didn’t change their minds. Politicians changed their voters.” A long-standing debate among academics asks how much of the longer decline can be attributed to partisan-motivated redistricting, known as gerrymandering, and how much to Americans’ increasing proclivity to live among like-minded people who vote the same way. Multiple studies have found that without partisan gerrymandering, the House would have about double the number of competitive seats it has now.
Competitive seats are districts in which a presidential candidate won by 5 percentage points or fewer in the previous election. Their number eroded slowly for decades after World War II as the United States grew more polarized, voters became less likely to split their tickets between parties, and people moved closer to like-minded neighbors, creating Democratic strongholds in urban areas and Republican ones across rural America. A count from the 1970s, when the shrinking number of such districts was first noted, identified 96 House seats that met the modern definition in 1964. The result is that the overwhelming majority of House seats are effectively won in primaries, with the support of only a fraction of voters who usually are at the extreme ideological end of their party.
Most of the scholars discussed agreed that the diminishment of competitive seats leads to greater polarization because legislators are beholden only to primary voters. “It produces more alienation because Congress doesn’t do anything besides investigations and positioning,” said Ian Shapiro, a Yale political scientist.
Republicans are hoping that the smaller number of competitive seats will put a low ceiling on what Democrats can win on Nov. 3. The Associated Press reported that the narrow battlefield may expand slightly in an unpredictable midterm year, though it remains narrow. Democrats have expanded their political targets amid the unpopular war with Iran and voter anger over high prices, and both parties are spending on campaigns in Republican areas that normally would not be competitive. Even in what is shaping up as a difficult political environment, Republicans are protected by the limited number of seats in play.
“Both sides are fighting over a narrow House battlefield,” said Mike Marinella, a spokesman for the National Republican Congressional Campaign. “It’s a knife fight in a dark alley.” Shapiro put a limit on what that field could deliver: “Even if there’s the kind of swing we got in 2006, there’s not going to be 40 seats changing hands. There’s going to be 20 seats changing hands.”
Unite America, an organization pushing alternatives to party primaries, calculated that 87% of the representatives elected to the House in 2024 were chosen by 7% of the country’s voters. “Voters don’t have any way of holding Congress responsible, except for a narrow window of swing districts,” said Nick Troiano, the group’s executive director, who expects things to get worse in November. “The least competitive election of our lifetimes will lead to the least accountable and least representative Congress of our lifetimes.”
Wiley Nickel, who saw the impact firsthand during his lone term in Washington, put the divide differently: “The biggest divide I found in Congress wasn’t Democrat versus Republican, it was safe seats versus competitive seats.” He added: “When your focus is on running a campaign where you talk to every single voter, you look at things differently and your focus is on solving problems.”
North Carolina’s 13th Congressional District shows what the map can change. In 2022, Democrat Wiley Nickel ran as a moderate and narrowly won the district by about 9,000 votes. Two years later, the current congressman, Republican Brad Knott, ran as a conservative and coasted into the U.S. House by more than 70,000 votes. The Republican-controlled legislature redrew the state’s congressional map, splitting the rectangular 13th District into an hourglass shape that carved out Democratic voters in Raleigh and replaced them with a swath of rural counties reaching up to the Virginia border. The Associated Press described the result as turning one of the South’s last remaining swing districts into a safe GOP seat.
Nickel decided not to run for reelection after studying election returns going back to 2016 and finding that no Democratic incumbent had held on in a seat where Trump took 55% or more of the vote. Trump received 58% of the vote in the new district. Nickel had introduced a bill requiring all states to use a nonpartisan redistricting system and initially said he would run for U.S. Senate because statewide seats cannot be gerrymandered. When former Gov. Roy Cooper announced he was running for the Democratic nomination, Nickel switched to run for district attorney of Wake County, the deeply Democratic county that was largely cut out of the 13th District. Nickel won the Democratic primary and will take office in January. No Republican ran. The Associated Press said the move highlights how North Carolina and the country have effectively become segregated by political party.
“If you just draw big blocks around a state, you’re going to get noncompetitive districts because we are so polarized,” said Joshua Huder, a political scientist at Georgetown University. Only 15% of North Carolina’s voting precincts could be classified as politically competitive, according to Michael Bitzer, a political scientist at Catawba College in North Carolina. “For the average North Carolinian, depending on where they live, if they drive an hour in any direction they will be in a very different North Carolina than they live in,” Bitzer said.
The contrast between the old and new districts runs about 90 minutes north from the office towers, cafes and gourmet restaurants of central Raleigh, which was part of the competitive 13th District, through subdivisions and soybean and tobacco farms that are the heart of the new, conservative one. Few people in the new district are talking about the congressional race. Many express dissatisfaction with the country’s direction but said they saw no reason to vote for anyone other than a Republican. “It’s just what I’ve always been,” said Linda Long, 62, a Republican in the town of Roxboro who works at the local Walmart.
The Associated Press reported that George Scott, 75, a retired architectural engineer in Franklinton, disliked Trump but remained a lifelong Republican who expected to keep voting that way. “It’s just one person,” Scott said of the president.
Paul Barringer is the Democratic nominee against Knott and hopes for an upset. The Associated Press wrote that the race came in a year when “even Republican members in safe seats like the 13th District are running scared.” Neither Knott’s office nor his campaign responded to a request for an interview. Barringer, a former healthcare lawyer who returned from Maryland to the tree farm in the district where he grew up to care for his ailing mother, said he was previously a Republican but switched parties to run, hoping to attract voters of all stripes. “I think people are disgruntled about things that are happening,” Barringer said. “They want people who will find ways to work together.”
On a recent evening, Barringer drove his 2011 Toyota Land Cruiser, with his two dogs in back, to the home of Mary Blank, who heads the chapter of the liberal group Indivisible in Johnston County, a fast-growing, conservative-leaning area just outside Raleigh. On the house’s back porch, he was greeted rapturously by a self-admitted political minority of liberals in the conservative area. Barringer reminisced about the task of curing tobacco and asked everyone who had undergone that rural North Carolina rite of passage to raise a hand. No one did. “We’re all transplants!” one woman called out.
There was palpable excitement, especially after Barringer noted that national Democrats had put the seat on a list of races to watch for a possible upset. Blank, a retired 73-year-old social studies teacher from New Jersey, said that gave her hope, but she was realistic about the local dynamic. “I’ve been saying all along I don’t think Paul can win,” Blank said. Linwood Parker, the 78-year-old mayor of Four Oaks, a town 26 miles south of Blank’s house, also doubted the Democrats’ chances. “They’re blowing smoke,” Parker said of Democrats’ hopes they could win the district. Parker, a lifelong Republican, said gerrymandering is a decades-old North Carolina tradition. He said Democrats used it to maintain control of the legislature and congressional delegation until they lost power in the 2010 wave, while Republicans now bend the maps to benefit their party. Parker said he approves of the current map even though he is no fan of gerrymandering or the polarization that has eroded bipartisan trust in society. “Redistricting is just one of the levers that when Republicans, when they’re in control, have to touch,” Parker said. “Otherwise it’s like saying, when we play this baseball game, we’re going to have three outs, we’ll give you two.”