“Dummymander” is a play on the term “gerrymander,” and it refers to a redrawing of a district map that actually ends up benefiting the opposite party that was designed to help.
When a political party in power reshapes the map of a district to gain advantage in an election, this is called “gerrymandering.”
“Dummymandering” occurs when that map, over time, actually ends up benefiting the opposite party (hence the use of the term “dummy).”
Simply put, it’s a gerrymander that backfires.
The term was coined by by Bernard Grofman and Thomas Brunell in their article, “The Art of the Dummymander.”
The risks of a gerrymander becoming a dummymander for either party are sometimes hard to measure.
The Washington Post explains how GOP gerrymandering leading up to the 2016 election could have backfired:
That strategy created so many marginal Republican districts that if the GOP loses the bulk of the seats at or below R+2, it would also lose its congressional majority. A catastrophe that claimed every GOP seat at or below R+4 would bring the GOP caucus close to the size of today’s House Democrats.
While the risk of dummymandering always exists, some political science experts argue that as techniques for redistricting improve, the odds of it happening are decreasing:
The ability to create the desired political effect increases every decade with advances in technology, making it easier for legislators and advocacy groups to target partisan precincts and predict their likely voting behavior for years to come.
“Dummymanders”–sociologist Bernard Grofman’s term for overly greedy gerrymanders that backfire– have become increasingly rare as sophistication about redistricting grows.
This was reinforced by Supreme Court justice Elana Kagan, as reported by New York Magazine:
Old-time efforts, based on little more than guesses, sometimes led to so-called dummymanders — gerrymanders that went spectacularly wrong. Not likely in today’s world.
Mapmakers now have access to more granular data about party preference and voting behavior than ever before.
County-level voting data has given way to precinct-level or city-block-level data; and increasingly, mapmakers avail themselves of data sets providing wide ranging information about even individual voters.
Still, with more and more gerrymandering comes the risk of more and more dummymandering.
In a 2015 Politico article that argued the merits of gerrymandering, the author acknowledges:
To be sure, gerrymandering schemes rarely create a statewide plan that is as competitive as it could be; the risk of dummymandering is too high.” The author goes on: “This happens when parties spread their voters just a little too thin, turning a gerrymander into a ‘dummymander.’ When an unfavorable political tide sweeps through, dummymandered districts switch parties, undoing the advantage the gerrymandering party had supposedly engineered for itself.