You don’t have these numbers right. There are currently two house vacancies.
Dave Cicilline (D-RI) resigned May 31, 2023. There is a special election to replace him scheduled November 7, 2023.
Chris Stewart (R-UT) resigned September 15, 2023. No special election scheduled yet.
These even out so five flippers would still be required, but I thought it might relieve some later confusion when inevitably during these negotiations we’ll hear the phrase, “Can they get to 217?” and now you’ll know why it’s not 218.