Were this election not immediately following a largely GOP-controlled round of redistricting, Democrats might have far fewer vulnerabilities of their own and many more appetizing Republican targets. But after Kansas became the last state to finalize its congressional lines earlier this month, the distribution of new districts told a scary before-and-after tale for Democrats. Using The Cook Political Report’s Partisan Voter Index as a measuring stick, our preliminary analysis indicates that the number of strongly Democratic districts—those with a score of D+5 or greater at the presidential level—decreased from 144 before redistricting to 136 afterward. The number of strongly Republican districts—those with a score of R+5 or greater—increased from 175 to 183. When one party starts out with 47 more very strong districts than the other, the numbers suggest that the fix is in for any election featuring a fairly neutral environment. Republicans would need to mess up pretty badly to lose their House majority in the near future.
An analysis of the race-by-race landscape tracks the partisan data pretty closely. The Cook Political Report rates 211 House seats as solid or likely Republican, compared with 171 as solid or likely Democratic. If the 24 toss-up races split evenly between the parties, Democrats would score a net gain of just a single seat. Even if Democrats held everything in their solid, likely, and lean columns and also won every toss-up, they would still need to take two-thirds (12 of 18) of the districts rated lean Republican to win a majority. That’s a pretty unlikely scenario, absent a strong wind at their backs.