Lots of commentary has been made about how many Republicans who crossed Trump (even if just occasionally) are losing their primaries to Trump-endorsed candidates. This has been portrayed as a show of strength. And I suppose it is in the sense that Trump has an increasingly iron grip over his own party.
But there is another way to look at this. Trump's support among the general public is in free fall. While Trump supporters remain loyal, the number of people who call themselves Trump supporters is going down. And since the modern Republican Party is Trump's party those who are not 100% on board are leaving the GOP.
So we have a shrinking party, with people leaving because they are disappointed in Trump. Which means that those who don't leave are the Trump loyalist who are left. It's a shrinking pool, but only the people who are still in the pool can vote in the GOP primary.
In other words, maybe Trump's recent primary victories is more of a reflection of the Republican party's overall loss with the total population. As the party shrinks the original coalition of MAGA plus "mainstream Republicans" (i.e. Republicans who disagree with Trump 1% of the time) starts to shed the mainstream Republicans. That leaves only the MAGA crowd who are going to listen to Trump when he tells them to slay his enemies in the primary. But that doesn't mean the party is strong, or that is will do well when the overall population votes. The Republicans who no longer feel at home in the party may stay home in the next election or cast a protest vote.
This is just my hypothesis. Maybe I'm wrong. Maybe it is just wishful thinking. But there are two clear trends: Trump's falling approval with the overall pubic, and Trump's better success at removing disloyal GOPers in the primary than he has had in the past. My hypothesis can at least explain both.