Because redistricting after the 2010 census was controlled by Republicans in state legislatures, there are more Republicans in Congress than would otherwise be expected.
| Election year | Partisan split in the US House | Artificial partisan advantage |
|---|---|---|
| 2012 | R 234-201 D | +25 Republican seats |
| 2014 | R 247-188 D | +5 Republican seats |
| 2016 | R 241-194 D | +17 Republican seats |
| 2018 | D 235-199 R | +22 Republican seats |
