The first for me was when Trump got COVID, was put on supplemental oxygen, given an unapproved drug cocktail that had not yet been tested. When he was finally released from the hospital he said people should not be afraid of COVID because it was no big deal, because doesn't everybody have access to 24/7 doctors and experimental drugs? Of course the base believed the "don't be afraid" part. The near death part was just hearsay.
Next was Trump taking credit for the vaccine. No doubt some help from the government helped get it done quickly. But the base had doubts that something done so quickly could possibly be safe. So he back tracked when he saw it wasn't popular with his base. Then after Biden whipped him, he told people not to trust Biden or the vaccine he had originally taken credit for. A stunning 180.
Then instead of accepting that the vaccine was effective at reducing symptoms and deaths, but would not prevent infection, the right wing base decided it was an evil liberal conspiracy to implant tracking chips. Now they believe Trump had nothing to do with the vaccine! He is the savior!