Below, Daily Kos Elections presents our chart of the results of the 2020 presidential election for the new congressional districts created during the 2021-22 redistricting process that will be used for the coming decade, starting in the 2022 midterms. For the sake of comparison, we have also included results for the same election under the old districts that were used in the 2020 elections.
All results were calculated by the Daily Kos Elections team. You can find the chart below in spreadsheet form here, as well as a version with vote totals here. The results are also shown in the map at the top of this post, which shows each district as equally sized (you can find a traditional map here). For a complete statement of the methodology used to calculate these results, as well as links to the raw election data underlying them, click here.
Note: Bolded predecessor districts differ in number from their corresponding new districts. Shading indicates that political and geographic predecessors differ from one another (more on those terms below).
Districts that are either brand-new or discontinued due to reapportionment are noted with dashed lines in the appropriate columns. Note that the chart above includes both old and new districts, so there are 442 in total rather than the typical 435.
In the right-most columns, we include our best assessment for each new district's corresponding predecessor districts. Caution is warranted, though, because making these assignments is not an exact science—some districts have clear predecessors, while others do not.
We assign predecessor districts in two ways: “political” predecessors and “geographic” predecessors. Geographic predecessors are simplest: They represent the old district that makes up the largest portion of the new district by population. As such, some new districts may share geographic predecessors, while some old districts (particularly those that have been broken into many small pieces) may lack successors altogether. Due to space limitations, geographic predecessors are shown in the right-hand columns of this spreadsheet version of the chart above.
Poliitical predecessors are more complicated. Our ultimate goal is to ensure that each new district (except for the seven brand-new seats created by apportionment) has one and only one political predecessor district after the 2022 elections are complete, and that each such predecessor district is unique—i.e., that no two new districts share a political predecessor district.
Our approach to making these determinations is generally incumbent-centered. Below are the considerations we rely on:
- District numbers can be helpful but they are not dispositive. Just because a new district shares a number with an old district does not necessarily mean the latter can be regarded as the political predecessor of the former. Maps are often renumbered, sometimes radically so, as California’s was following the 2010 round of redistricting.
- If an incumbent is seeking reelection, our presumption is to regard the old district they previously represented as the predecessor of the new district they are seeking to represent. Given the high proportion of House members who seek reelection (an averge of about 90% between 2006 and 2020), this presumption guides most of our decisions.
- We follow the presumption above even when an incumbent runs for a new district with a number different from that of their old district.
- For example, following the 2010 round of redistricting, Democratic Rep. Jim Matheson sought reelection in the new UT-04 even though his prior district was the old UT-02. We therefore designated UT-02 as the political predecessor of UT-04.
- In cases where an incumbent had not yet announced which district they will run in, we assigned them to the district we believe they are most likely to seek.
- For example, Democratic Rep. Kurt Schrader could have conceivably sought reelection in either OR-05 or OR-06, but his hometown of Canby is located in OR-05, so we assigned him to that district. Schrader did ultimately decide to run in OR-05 (though he lost in the primary).
- Similarly, if an incumbent retires but it’s reasonably clear where they would have sought reelection, then we will assign political predecessor districts accordingly.
- For example, following the 2010 round of redistricting, Democratic Rep. Gary Ackerman was planning to run in the new NY-06 before announcing his retirement, so we designated his prior district, the old NY-05, as the political predecessor district.
- If two incumbents face off against one another, we designate both districts as political predecessors. When one wins, we remove the loser’s district and leave only the winner’s as the political predecessor. We follow this procedure for both primaries and general elections.
- For example, following the 2010 round of redistricting, Rep. Mark Critz, who represented the old PA-12, and Rep. Jason Altmire, who represented the old PA-04, ran against one another in the Democratic primary for the new PA-12. After Critz won the primary, we designated the old PA-12 as the political predecessor of the new PA-12.
- If a district was newly created due to reapportionment, then we have not designated any political predecessor.
- For example, Oregon earned a new district following the 2020 census, which is numbered OR-06. Note that “new” districts are not always those with the highest number in their state. This can be due to renumbering (as in the California example above) or because of decisions incumbents make when seeking reelection (as in the Utah example above).
- Conversely, in states that are losing one or more districts due to reapportionment, a commensurate number of old districts will always lack a successor.
- For example, Pennsylvania lost a district following the 2010 census, resulting in the primary described above between Critz and Altmire. Because Altmire lost, his district, the old PA-04 has no successor.
We generally do not rely on data showing how the population has been redistributed from old districts to new districts (which we calculate separately here) in order to make assessments about political predecessors; instead, we use this data to assign geographic predecessors. There are two main reasons for this.
First, we believe that an incumbent’s decision about where to seek reelection says more about political continuity between districts. For instance, a representative’s old district might get divided between new districts, one that has 60% of the population of the old district and another that has 40%. The incumbent’s home, however, might wind up in the latter, prompting them to seek reelection there, even though more of their constituents have wound up in the former.
Second, using population figures would often make it appear that two districts share the same predecessor. For example, following court-ordered redistricting in 2018 in Pennsylvania, the new PA-08 and PA-09 both traced their ancestry to the old PA-17 because it provided a plurality of the population for both new districts. In practice, however, the new PA-08 was properly designated the successor of the old PA-17 because Democratic Rep. Matt Cartwright, who represented the latter, chose to seek reelection in the former. (We also determined that new PA-09’s predecessor was the old PA-11.)
We take an incumbent-centered rather than electorate-centered approach to determining political predecessor districts because, in the end, elections are won and lost by individual candidates, and that’s the lens through which we most frequently discuss politics. But we still believe it’s important to analyze how electorates flow from old districts to new because, of course, it’s those voters who will decide elections, which is why we assign geographic predecessors as well.
In rare instances, our incumbent-centered approach will lead to outcomes where there’s little or even no overlap between a new district and its political predecessor. For example, following the 2010 round of redistricting, which saw California’s map radically redrawn, Republican Rep. Gary Miller chose to seek reelection in the new CA-31, even though none of his constituents from the old CA-42 lived there. That fact, though, is the sort that we’d be certain to take note of in any discussion of a race like that.
For presidential election results for the 2016 and 2012 presidential elections (under old district lines), click here. For all of our district-level election calculations, click here.