Trump has shaped the Republican party. When Bush was President, the Republican party was dominated by NeoCons like Bush and Cheney. This gave it a very elitist image. Important, but less influential were the Tea Party Republicans and Libertarians, they had some impact on policy but little real power.
Then Trump transformed the party with his conservative populism. His protectionist policies including securing the border, tariffs, and fair trade (vs free trade) attracted millions of wage workers into the party. The Republican party has replaced the Democratic party as the party of the hourly wage earning American.
Meanwhile his tax policies and reluctance to issue behavioral mandates strike a chord with Tea Party Republicans and Libertarians.
Meanwhile many of the never Trumpers were NeoCons like Liz Cheney and they are such a small percentage of the party, that their impact is minimal and fading.
So, Trump and the term MAGA are likely to fade after 2024 if Trump does not get elected. But the Republican that does will likely incorporate and embrace many of Trump's policies are popular with the majority of Americans.
Perhaps the most important poll you should pay attention was the recent poll which observed Republicans more than ever do not respond to polls.
"The survey found that 11.7 percent of Republicans and 10.5 percent of independents wouldn’t tell phone pollsters who they were voting for. Only 5.4 percent of Democrats said the same thing."
If you want to take some solace, Schumer's comment overheard at a recent dinner with fellow Democrats suggest that the House will be lost, but the Senate could go either way.
If that is true, regardless of whether the Dems hold the Senate this year, in two years, they will have 9 Senate seats up in swing states.
All of this points to a lame duck Presidency followed by the Republican pulling off a sweep in 2024. The only younger Democrats with any visibility are people like Gavin Newsom, not exactly someone to attract the independent vote.