That’s because few people knew who Trump really is back in 2016. Anyone who’s been paying attention has known for forty years that he’s a sleazy crook (thank you, Spy Magazine). Everyone else, which is practically everyone, thought that he was the charming You’re Fired guy from TV. They also thought he would be a politician within a certain range. Everybody knows just who Trump is now, and they either love him or loathe him, and there are a lot more people in that second camp now, and that camp will continue to grow until November 2024.
All those people I hear on C-SPAN in the morning who say they voted for Biden and Hillary and Obama twice and Clinton twice but are going to vote for Trump now are either lying or are agents.