"Breaking" The Economist poll has Trump

[ProfessorGAC]

16. Not Working For Me

The cult hasn't turned on him. These polls don't reflect the "only Trump" voters. They reflect everyone else.
It's independents who voted for him.
If independents never voted for a dem/liberal, Obama & Biden wouldn't have won, and Hillary wouldn't have won the popular vote.
Besides, nearly every poll, national & regional, has him underwater on nearly every issue.
Why would this poll be an outlier?
As to your last question, Rs in Congress are worried about being primaries. Standing up to him has nothing to do with their confidence, or lack thereof, in polls. It's about protecting their cushy jobs against resistance from the right.
Finally, remember that even in 2024, The Failure only achieved a plurality win. It's not like some overwhelming majority thought he was a good choice. He lost the popular vote in '16 & '20, and won without a majority in '24.
Sure doesn't suggest invincibility.