You need to replace these people through primaries.
The primaries where the party selectively protects centrist incumbents like Henry Cuellar, but not progressive incumbents like Cori Bush or Jamaal Bowman. The primaries we didn't even get in the 2024 presidential election. The primaries that the party successfully argued in court that they don't have to run honestly.
Don't treat primaries like a panacea to people who no longer trust the primary process.