I think the problem is twofold.
Misinformation on social media...anti vax, conspiracy theories and the religious extremists who claim (lied)God told them Trump will win.đ
AND a press that compounds all this with a blatant left wing bias.(I'm left wing by the way and it even annoys ME as Ive always had a strong sense of fair play ) So some supporters see him as a victim of some nefarious globalist deep something or other who knows rather than what's really happening also. A combination of a huge swathe of American youngsters attending university and so more educated folks than ever before (whether you find what they learn Marxist or not) and certain underprivileged groups finding their voice. And then add a pandemicđ
And of course all this list plays out on so many platforms which exacerbates it all in our minds.