Trump isn't the problem - he's just a symptom.
He didn't have to be the President. He didn't even have to be the Republican nominee. Voters could've picked somebody else during the primary process... The Republican party could've outright rejected him... Or voters could've picked somebody else during the general election.
Right now, today, after the disaster of the last four years, Trump still has about 43% approval according to 538. And the Republican party is still standing behind him. That's millions of people who think he's doing just fine. Millions of people who are probably going to be voting for him again.
They are the problem. All those people who want this for the country.