North Carolina’s 13th Congressional District offers a stark example of how partisan redistricting and long-term political polarisation have reduced the number of competitive seats in the US House of Representatives, analysts say. What was a narrow Democratic victory in 2022 became a decisive Republican win two years later after the state’s Republican-controlled legislature substantially altered the district’s borders.
From swing to safe in two years
In 2022, Democrat Wiley Nickel won the 13th District by about 9,000 votes, running as a moderate in a seat that remained one of the South’s last true battlegrounds. By 2024, Republican Brad Knott carried the same numbered district by more than 70,000 votes. Voters did not dramatically change their views; rather, the district’s composition changed. Lawmakers split the rectangular district into an hourglass shape that removed Democratic voters in Raleigh and extended the district through a corridor of rural counties up to the Virginia border.
The effect was immediate: a previously competitive district shifted to a comfortable Republican margin, reinforcing the broader national trend documented by analysts observing the House map.
Long-term trends accelerated
For decades after World War II, the number of competitive House seats — those that a presidential candidate won by no more than five percentage points — declined gradually. Three factors are commonly cited:
- increased political polarisation among voters;
- a decline in ticket-splitting, with more voters supporting the same party across races;
- geographic sorting, as people increasingly live near others with similar political views, creating concentrated urban Democratic areas and rural Republican ones.
Those dynamics were compounded in the most recent redistricting cycle, which observers say accelerated the loss of swing seats. One recent count found the number of such districts fell from 45 to 37 over the last year — a rapid shrinkage that reduces the number of districts that can be won in general elections and increases the role of primaries in deciding representation.
| Reference point | Number of swing seats |
|---|---|
| Circa 1964 (modern definition) | 96 |
| Recent count (before latest redistricting) | 45 |
| After most recent changes | 37 |
"The biggest divide I found in Congress wasn’t Democrat versus Republican, it was safe seats versus competitive seats," said Wiley Nickel.
Nickel’s observation points to a deeper institutional consequence: where most districts are safe for one party, general elections often become formalities and the decisive contests shift to party primaries driven by more ideologically motivated voters. That, in turn, can reward more partisan behaviour and reduce incentives for compromise in Congress.
Consequences for governance
With fewer competitive districts, representatives are more likely to be elected by a smaller, highly motivated segment of the electorate. Some analysts argue this concentrates power in the hands of the most partisan voters and makes elected officials less responsive to the broader electorate’s demand for pragmatic problem‑solving.
While the example from North Carolina is striking, it mirrors a national pattern: legislative control of redistricting processes, combined with demographic changes and shifts in voting behaviour, has reshaped the electoral map in ways that may make Congress less representative of the centre of public opinion and more prone to stalemate.
As the US heads into future election cycles, the trajectory of competitive seats will be an important indicator of whether reforms — such as independent redistricting commissions or changes to primary systems — gain traction as remedies to the increasing nationalisation and polarisation of American politics.
