He’s basicaly a non-entity at best, but more likley a total liability, but the larger issue at hand, is that a more astute right wing republican will take his place.
The problem is that he still has very strong support among Republican base voters.
About 30% of voters are registered Republicans (maybe a bit higher, but below 40%, I believe).
To run for Congress, a Republican first has to win nomination by their party. They need 50% + 1 votes in a Republican primary. Even though only 20% of voters are hard-core MAGA voters, that’s a majority of Republicans in red states. Those red state seats are safe Republican seats, therefore, MAGA candidates dominate the Republican caucus.
Mainstream Republicans like Mitt Romney and Liz Cheney (who are staunchly conservative, but fundamentally honest) know that the MAGA nuttery drives moderate voters away, but the MAGA core of the Republican voters don’t care – they aren’t interested in assembling a governing coalition and crafting a pragmatic policy portfolio that will generate enough mainstream support to be enacted, they are only interested in performative stunts to demonstrate their distain for anyone who disagrees with them.
So, basically, the Republican party is dominated by nutters who aren’t interested in actually governing. They know that Trump is toxic and drives away moderates, but they think that owning the libs is the purpose of getting elected so they back Trump because he drives away moderates, not in spite of it.