The problem for Democrats is that these emerging landslide counties almost exclusively vote for Republicans. The thing about counties, though, is that their boundaries don’t change. This means that the massive geographic advantage Republicans enjoy cannot be blamed solely on gerrymandering.

The real explanation is the geographic sorting of the two parties over the past 30 or more years. Democrats have diminished as a presence in rural counties, particularly in the South and Midwest, while gaining numbers in counties with large cities like Los Angeles, Houston and Chicago.

These latter areas have such large populations that by winning them decisively, Democrats can stay competitive nationally despite Republicans’ more even geographic spread of support across the country.

The data largely indicates that it is this phenomenon, not gerrymandering, that is responsible for Democratic electoral underperformance. The clustering of Democratic votes in big cities makes it more difficult for any entity – including courts and nonpartisan commissions – to draw district lines that get Democrats the most possible seats in Congress. Because Democrats live in denser, more tightly packed places, they can’t distribute their votes as efficiently among geographic districts throughout a state.

Meanwhile, because Republican support is more evenly distributed geographically, there are more and better options for them to win lots of districts, rather than just lots of votes. Put simply, because of where they tend to live, Republicans are wasting fewer of their votes than Democrats.

None of this means that partisan gerrymandering is not happening, or that efforts shouldn’t be made to fix it.

If both parties are gerrymandering so effectively that they cancel out each other’s gains, this has major implications for political institutions and culture even if they aren’t reflected in the national balance of power.

Gerrymandering has been increasingly the subject of court challenges, further bringing politics into the supposedly nonpolitical U.S. judicial system.

It also has tangible effects on regular Americans. My own research shows that changing district lines can disorient voters and reduce turnout. It could also cut into voters’ sense that their votes make a difference.

Democrats from South Carolina and Republicans from Illinois, would, I believe, feel better represented if they could see delegations that more accurately reflected their state’s electorate.

Additionally, partisan gerrymandering often means disregarding important local city and county boundaries, as well as local cultures, neighborhoods and industries – what political scientists call “communities of interest” – that have little to do with partisanship but mean a lot to everyday people.

This article is republished from The Conversation, an independent nonprofit news site dedicated to sharing ideas from academic experts. The Conversation is trustworthy news from experts, from an independent nonprofit. Try our free newsletters.

Read more:
Speaker of the House faces political peril from member deaths and resignations – especially with a narrow majority

The ‘carpetbagger’ label that Fetterman stuck on Oz may have been key in defeating him

Charles R. Hunt does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.