I think there are about three things in play here:
Quite a lot of the republican base lives in a completely different reality thanks to campaigns of propaganda and destroying education. Charitably, the best way to describe these people is extremely ignorant. For them, these indictments are dem led witch-hunts that they mostly don’t believe, even when you can literally see the opposite. EG: Should presidents take classified documents? No. What are these pictures? those are classified documents at maralago. Did Trump do something wrong? Now let me tell you about Hunter Biden and the Biden crime family…
Quite a lot of republicans are bordering on sociopathy if not pure evil. The party in particularly, and not the voters, know they’re peddling bullshit but they don’t care because it’s going to get them more money/power, which is the only real goal/ideology. Then you have the white supremacists and fascists that are just evil and are doing this for ideological reasons.
Systems are designed in this country to perpetuate this. Literal minority rule is a founding principal of this country.
I think there are about three things in play here: