This helps explain why Republicans have controlled the Pennsylvania State Senate for nearly four decades, despite losing statewide votes about half that time. It explains why Republicans are routinely overrepresented in state legislatures, even in blue states like New York. It explains why Hillary Clinton carried only three of eight congressional districts in Minnesota — districts drawn by a panel of judges — even as she won the whole state.
In most European democracies, geography doesn’t matter in the same way. Legislators are elected from larger districts, each with multiple representatives, granting parties proportional power. If a party wins 50 percent of the votes, it doesn’t matter much if those votes are evenly spread around or tightly clustered.
Britain, Australia and Canada, unlike much of Europe, have the same majoritarian system the United States does, and urban-rural divides appear there, too. Underrepresentation of the left, Mr. Rodden argues, is a feature of any democracy that draws winner-take-all districts atop a map where the left is concentrated in cities.
In the United States, two features make this polarization even more powerful. Gerrymandering, a particularly American practice, allows Republicans to amplify their advantages in the political map. Democrats gerrymander, too, but often the most they can achieve is to neutralize their underlying disadvantage.
The U.S. also has an inflexible two-party system. That results in our political disagreements being drawn into the urban-rural divide. Today the urban party is also the party of the knowledge economy, of gay marriage and gun control. The more rural party is also the party of stricter immigration, of abortion restrictions and religious liberty.
We keep adding more reasons to double down on geography as our central fault line, and to view our policy disagreements as conflicts between fundamentally different ways of living.
Recent history has obscured the consequences of all this for the Democratic Party, which controlled the House for nearly all of the postwar period leading up to the Gingrich Revolution in 1994. Democrats were able to do that — and to retake the House in 2018 — by winning seats on what resembled Republican territory. Democrats need moderate “blue dogs,” Mr. Rodden argues, to overcome their geographic disadvantage.