The trouble is, a lot of people are using the terms very loosely, which is not helpful.
Some people’s relationship to Trump is the same as cult members to their charismatic leader. This is an issue, but it doesn’t cover every Trumpist. For them, they are treating Trump as more than human, and the idea of holding him to human standards like justice is blasphemous.
Others are more or less brainwashed, not by Trump’s apparent charisma, but by the large amounts of propaganda they’ve been fed over time via Fox etc. This group, similarly, regards Trump irrationally, but for them it’s more because Democrats / Deep State / Lizard people / whatever are doing nefarious things, and Trump is merely the underdog victim of a vast conspiracy.
Both of these two groups are irrational, and a real problem, but I think they function quite differently. I’m sure there’s some overlap, of course.
Meanwhile, there are the self-interested amoral Republicans, who are playing to win: they’re backing Trump out of perceived self-interest, and are willing to throw the nation’s norms and institutions under the bus for their own power. This is what I’d refer to as deplorable. These people, also a problem, have no illusions about Trump, but are attempting to ride the tiger for their own gain.
Then there are the R-voters who will hold their nose and vote for Satan’s lawyer if that demon will appoint conservative judges / veto abortion / punch an immigrant / drown a sack of kittens / whatever their single issue is. These people are also acting in rational perceived self-interest, but could be swayed by arguments.
Finally, there are the low-information voters who don’t know or care much about anything and who can be swayed by an emotion-laden sound bite. These people can be salvaged by going back in time and investing in a robust public education system that also teaches civic duty.
Edited: I think Trump’s indictment would just drive the cultists and the brainwashed further into their delusions; the self-interested will make plenty of use of it, but otherwise it will have little effect. If anything, it seems to me that it will help Republicans overall.