You have to take Pres Trump’s influence on a case by case basis. It’s not necessarily true that his grip on the GOP is waning, it just works in some places and not in others. Ohio for example makes sense, maybe Nevada, PA-GOV for sure (senate TBD), but Georgia is not a MAGA state, and poll after poll shows it’s just not breaking through. That’s a good thing IMHO.
Gut check this. Why would Trump's endorsement matter more in PA-GOV than PA-SEN? If it does, it's because other factors (like candidate quality or fundraising) matter more than his endorsement does.
Trump's endorsement seems to be a lagging indicator rather than a leading one. That is, his picks have tended to confirm where Republican primary voters are already going rather than being the catalyst for getting them there.
Just to remind you something:
Every single Candidate Trump endorsed overperformed the Polling in the Primaries dating back to Texas on March 1st. That says a lot.