The number of congressional districts that vote for a House representative and a presidential candidate from opposing parties has plummeted from 190 in 1972 down to 16 in 2020.
Why it matters: The stark numbers are likely a product of the shrinking number of elected Southern Democrats and worsening polarization in the U.S., as well as the decline in competitive districts because of redistricting and the clustering of like-minded populations.
The big picture: For years, Democrats were more likely to win seats in districts that voted for the Republican presidential nominee than the other way around.
- Between 1972 and 1988, the vast majority of split-ticket districts were won by House Democrats, according to Pew Research Center. They were also disproportionately in the South, which accounted for 41.2% of all split districts.
- In the last three presidential election years, however, the trend has reversed: Republicans have managed to win more House seats in districts that voted for the opposing party's presidential candidate than Democrats.