The United States might seem like a nation evenly split between Republican red and Democratic blue when looking at national election results. However, this perception doesn’t reflect the growing reality in many parts of the country, where political competition at the local level is being replaced by a strong allegiance to a single party.
In recent years, counties that Republicans were winning by 20 points at the start of the 21st century are now seeing margins of 50 points or greater. Concurrently, the number of counties that switch allegiances between parties during each presidential election cycle has diminished.
According to data collected by the NBC News Political Unit, demographic trends have clearly defined our current political groups. Additionally, geographical trends highlight the extent to which this reorganization has concentrated along community lines over the past 25 years. It’s becoming increasingly common for individuals to have political discussions only within their own echo chambers, as the political clustering in the United States has made it more feasible than ever to avoid opposing views.
Looking at blowout county wins
George W. Bush’s Electoral College win in 2000 was famously razor-thin. But his average win across the country’s 3,100-plus counties was about 17 points. Democrats’ advantage in population-dense urban cores bolsters their popular vote count election after election. But Republicans’ advantage in rural counties has been a core part of the Republican playbook, with small-county wins with margins of 50 points or more adding up, bit by bit, to a substantial coalition. These were the counties where each candidate had 50-plus-point-margin wins in the 2000 election:
Bush captured major wins across the Plains states and up through the Mountain West, while Al Gore racked up margins of 50-plus points in the densely populated New York City boroughs, Philadelphia, Baltimore and some scattered rural areas with large Black populations.
But more than two decades later, President Donald Trump has dramatically expanded the number of blowout win counties.
Trump has grown Republican political advantages east of the older GOP bulwarks and has captured Appalachia, which was once a reliably Democratic region, continuing to drive up margins in rural America. The average size of a Trump blowout county was about 10,000 voters last year. On the flip side, Democrats have grown their advantages in population-dense cities and suburbs, with the San Francisco Bay Area; Portland, Oregon; and Seattle emerging on this map as heavily Democratic areas. The average size of a blowout county for Kamala Harris was 210,000 voters.
Some of the most important political coalitions for Democrats emerge on this map, especially in comparison with 2000. The 2024 map shows the birth of Democratic vote powerhouses in majority-Black DeKalb and Clayton counties in Georgia and in Wisconsin’s Dane County, home of Madison and the University of Wisconsin, with its heavily white and college degree-holding population. Both coalitions are essential to Democratic wins in those states in recent elections.
Overall, there are four times as many blowout counties today than there were at the turn of the century.
Counties flipped
One consequence of the sharp rise in blowout counties: a precipitous decline in swing counties.
Back in the 2004 election, 227 counties flipped from one party to the other compared with the 2000 election. But last fall, only 89 changed their party preferences from the 2020 election.
The total number of flipped counties has dropped over the century. The biggest spikes occurred in the 2008 first-term election of Barack Obama and the 2016 first-term election of Trump — moments when the party coalitions changed dramatically.
Trump’s 89-county flip in this last election was actually an increase over the 80 counties that flipped in Joe Biden’s victory in 2020. The last election was also statistically notable for another reason: Harris became the first candidate this century who didn’t flip a single county compared with the previous election.
