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Gerrymandering Competitive Districts to Near Extinction

The House is still up for grabs, but which party gains control will be determined by races in an increasingly small number of districts.

Map being cut up and taped back together
Brennan Center/mikroman6/fotograzia/Yulia Reznikov/Getty
View the entire Assessing the Redistricting Cycle series

One of the most consequential outcomes of this redistricting cycle has been the continuing decrease in the number of competitive congressional districts. Under new maps, there are just 30 districts that Joe Biden won by less than eight percentage points in 2020 and, likewise, just 30 districts that Donald Trump won by less than eight points.

All told, there are now fewer competitive districts than at any point in the last 52 years. If the good news is that both parties emerged with reasonable opportunities in coming years to win control of a closely divided House, the bad news is that they will fight that battle on the narrowest of terrains under maps artificially engineered to reduce competition.

Though the number of competitive congressional districts in the current House was already small, this redistricting cycle, we saw the percentage of competitive congressional districts fall even further to just 14 percent. This is significant because as a district leans further toward one party or the other, the general election becomes increasingly insignificant while the favored party’s primary becomes the real contest. As a result, primary voters can effectively decide which candidate will represent the district in Congress, even though they make up a small fraction of the electorate and are often far more partisan than the average general election voters. Candidates elected in these districts then have little incentive to woo moderate voters in campaigning or legislating, further increasing the House’s partisan polarization.

Unsurprisingly, partisan map drawers drove the decrease in competitive districts. In Republican single-party controlled states, the percentage of competitive seats fell from 16 percent of districts before redistricting to just 12 percent after. The decline in competitive seats in Democratic single-party controlled states was even more precipitous, falling from 12 percent to just 6 percent.

Yet these percentage point decreases only tell part of the story: Republicans control the map drawing of far more seats than Democrats do, and although the states controlled by Democratic mapmakers saw a sharper percentage point decrease in competitive seats, the actual number of competitive seats lost in Republican-controlled states is almost triple that of Democratic-controlled ones.

By contrast, states where commissions or courts drew maps either saw the percentage of competitive districts fall only marginally or even increase. Indeed, after the steep decline in competition in single-party controlled states, maps drawn by commissions or courts now account for almost 60 percent of the nation’s shrinking number of competitive districts. To be clear, independent commissions like those in Michigan and Colorado differ in important ways from the politician-appointed, bipartisan bodies in states like New Jersey and Montana, but they all require participation from both major political parties. When the commission states are considered together, there is only about a 15 percent decrease in the share of competitive seats, far less than the drop in competition that occurred in states where one party drew the map.

But while both parties were aggressive in reducing the number of competitive districts in the states that they controlled, their strategies diverged.

For Democrats, a major handicap heading into redistricting was the lopsided map-drawing advantage that Republicans held. With a virtual lock on control of redistricting in the seat-rich South, Republicans started out the cycle with expected control of the redrawing of 187 congressional districts, while Democrats would control only 75. And worse for Democrats, many of their states were places like Massachusetts or Maryland where they already controlled all or nearly all of the seats, meaning that there were few if any pick-up opportunities.

The small number of opportunities available to them created major competing pressures for Democrats. On the one hand, they faced pressure to create new Democratic districts in the states they controlled to offset massive gerrymandering expected in Republican states. At the same time, they faced the usual pressure to shore up vulnerable incumbents and hold on to the seats they already had.

In the end, Democrats split the difference. Rather than increasing the number of super-safe districts that Biden won by more than 15 percentage points in 2020, they instead increased the number of districts that he won by 8 to 15 percentage points — creating solid Democratic districts but ones not conceivably out of reach for Republicans in the right election cycle.

Republicans did the opposite. Faced with the twin challenges of demographic change and the unanticipated shift of college-educated white voters toward Democrats, Republicans prioritized ultra-safe districts.

Texas is a case in point. For each of the prior two redistricting cycles, Texas Republicans’ strategy had been to maximize GOP-held seats wherever possible. But that aggressive, seat-maximizing strategy almost backfired last decade. An infamous gerrymander that divided liberal Austin among six districts had come close to being a “dummymander” by the end of the decade as Austin’s population boomed and made districts that included any part of it increasingly more Democratic. Likewise, districts in the rapidly diversifying and politically volatile suburbs of Dallas and Houston had unexpectedly evolved into some of the most competitive in the country. Indeed, by 2018 and 2020, Texas had become an unexpected ground zero in the battle for control of the House.

With this round of redistricting, Texas Republicans’ strategy would shift from maximizing seats to creating ironclad safe districts even it if meant leaving some vulnerable Democratic incumbents in place. Whereas before redistricting, 12 of the state’s then 36 districts had been competitive, under new maps, only 3 of 38 districts are — and two of them just barely. Moreover, virtually all Republican districts in Texas are not only safe, but ultra-safe. In all, a remarkable 88 percent of Republican districts in Texas are now ones that Donald Trump won by 15 or more percentage points — significant insurance against the demographic change and suburban political shifts that bedeviled Republicans last decade in Texas.

But as dire as the story on competition is, it could have been worse if maps originally passed by New York’s legislature had not been struck down by courts and redrawn by a court-appointed special master. Under New York’s court-drawn map, almost one in five seats are competitive, the highest percentage in the country for a large state. Had the map passed by the Democratic-controlled legislature remained in place, no districts would have been competitive.

In the end, a closely divided House remains up for grabs, with reasonable opportunities for both parties to win control in coming years. However, barring unforeseen political shifts, most voters will watch that fight from the sidelines due to maps that artificially reduce competition. If Americans hope to reverse the long-term decline of competitive districts, reforms to create fairer, more independent map-drawing processes will be essential.