“only 121 of those 293 B.T. (Before Trump) Republican legislators (41 percent) still have an office on Capitol Hill.
Some of this, of course, is normal attrition. Nineteen of the Republicans who left Congress did so to seek another office, something House members do all the time. Thirty lost a general election, indicating they didn’t want to leave Congress. Some of the 70 who retired from elected office, such as 82-year-old former Rep. Kay Granger, probably did so for age or health reasons rather than political ones. There were even four Republican members of Congress who died in office.
But some undeniably left because they no longer fit in in Trump’s GOP. Most obviously, 10 lost a primary election to a fellow Republican, including former Reps. Liz Cheney, Jaime Herrera Beutler and Tom Rice, who all faced a Trump-backed primary challenger after voting to impeach him in 2021. Several others, like Trump critics former Sen. Jeff Flake and former Rep. Adam Kinzinger, likely chose not to run for reelection because they were worried they would meet the same fate. Other departed Republicans, like former Sen. Rob Portman, former Speaker Paul Ryan and former Rep. Ken Buck, expressed frustration with the direction of their party on their way out the door. Two, former Reps. Justin Amash and Paul Mitchell, even left the Republican Party before retiring from Congress.”
https://abcnews.go.com/538/gop-trumps-party-now/story?id=118574467