I do not see the Republicans changing course, because either the people are fed up with Trump and MAGA in the next election, then imho the Democrats win, or MAGA turns out to be a blessing and the US prospers and becomes a great country again. Then MAGA will stay and a new president will need Trump's blessing and Trump will still dictate the course of the party.
At the moment it looks like the second outcome is likely, as Trump is doing very good.