Month: December 2022

“The 2022 election for the House of Representatives was so close1 that if any number of things had gone differently, Democrats might have kept their majority. And one of the biggest things that affected the battle for the House was redistricting — the decennial redrawing of congressional districts’ lines to account for the results of the 2020 census.
But was the impact of redistricting significant enough to swing the House to the GOP? As I wrote in June, the 2021-22 redistricting cycle didn’t radically change the partisanship of the national House map, so I mostly agree with those who say redistricting didn’t cost Democrats the House. But at the same time, those who say Republicans won only because they gerrymandered are also technically correct. How can both things be true? Allow me to explain.

One way to test the claim that “redistricting cost Democrats the House” is to assess whether Democrats would have held onto the chamber if redistricting had never happened. We at FiveThirtyEight have already calculated how many percentage points each district swung left or right thanks to redistricting. For example, a district that went from a partisan lean2 of R+2 to D+3 got 5 points bluer. Then I compared this swing to the current 2022 House margin in that district.3 Suppose a party lost by less than the district swung away from that party in redistricting. In that case, it’s likely that redistricting cost that party the seat.

Of course, this is a hypothetical — and imperfect — exercise. Some districts changed substantially and wouldn’t have swung uniformly like that had they not been redrawn.4 In addition, if they had not changed, different districts might have attracted different candidates and different levels of spending from national groups, each of which could have affected the result. But this method can still give us a rough idea of what might have happened in a redistricting-less world.

Using this method, we can see that Republicans flipped a net six seats because of redistricting.”

…

“But Democrats also caught a few bad breaks in states with ostensibly nonpartisan redistricting processes. For example, the Arizona Independent Redistricting Commission made the 2nd and 6th districts5 about 10 points more Republican-leaning. In Michigan, the state’s Independent Citizens Redistricting Commission redrew the 10th District6 to be light red. And court-appointed experts nudged the New York 17th and Virginia 2nd rightward enough that they flipped too. Meanwhile, Democrats on the New Jersey Congressional Redistricting Commission voluntarily sacrificed the 7th District to protect vulnerable Democrats in other districts.

On the other hand, Democrats flipped a few seats thanks to redistricting. They drew some very Democrat-friendly maps in Illinois and New Mexico, enabling them to pick up the Illinois 13th and New Mexico 2nd. A court reconfigured North Carolina’s 13th District from a solidly red seat into a swing district that Democrats narrowly carried. And Republicans made the Ohio 1st District and Texas 34th District bluer, with the unfortunate (for them) side effect of handing those seats to Democrats.

But we also need to consider seats that didn’t flip but would have if redistricting had not occurred. And this is where Democrats benefited the most, gaining six seats on net — and canceling out Republicans’ gains from the flips that did occur.”

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“Democrats also gained a net three seats from reapportionment, the process of subtracting congressional districts from states with sluggish population growth and giving them to states whose populations have exploded. Six of the seven districts that were eliminated by reapportionment were held by Republicans — slow-growth areas tended to be in rural and/or postindustrial areas, where Republicans usually dominate. But Republicans won only three of the seven districts that were created in reapportionment, for a net Democratic gain of three seats.”

…

“By my reckoning, Democrats actually gained three seats from redistricting overall. In other words, without redistricting, Republicans’ majority would be closer to 225-210.

“But wait,” I hear you saying. “There was no world in which redistricting wouldn’t have occurred in 2021-22. So isn’t it better to calculate how the 2022 election would have gone down if redistricting had gone differently, not if it hadn’t happened at all?” You have a point — but the problem is, there is no objective alternative map. The congressional map could have changed in a thousand ways depending on individual, state-level decisions.”

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“[If redistricting went differently in a number of ways in favor of the Democrats,] Democrats probably would have won five more seats than they actually did.”

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“five additional seats for Democrats would have been enough for them to hold onto a slim 218-217 majority. So yes, if every Republican gerrymander had been undone in court before the 2022 election, Democrats may have kept control of the House.

But that’s assuming no additional Democratic gerrymanders were thrown out in court.”