It is already evident that at least one out of every eight members of Congress will not be returning in 2027, as either they are retiring; have lost renomination; or are running for another office other than the one they now hold.
Eleven US Senators and 59 House members are definitely leaving, with 7 Republicans and 4 Democrats leaving the Senate, and 38 Republicans and 21 Democrats leaving the House of Representatives.
So a total of 45 Republicans and 25 Democrats are leaving Congress.
This does not include those members of Congress who have died or resigned during this two year term.
The aging of Congress is a factor, but also those who desire to move on to another political goal, or are facing the reality of primaries and also the reapportionment of seats by gerrymandering that will eliminate others who had planned to run for reelection.
So the future 120th Congress (2027-2029) will have record turnover, and it is certain, there will be more “new” members of both houses of Congress, than just the present number of 70 members leaving.