At What Point Do Trump’s Insane Rants Become Counter-Productive?

My conservative mother points out that, whenever Trump is attacked, his popularity rises.

There does seem to be some truth here, though perhaps the causal element here is simply that his name stays in the news. For example, the media loves Trump’s Christmas post here, in which he expresses his hope that all progressives ROT IN HELL (emphasis his).

Of course, that’s not a very Christian thing to wish, but isn’t that the point?  It needs to be sufficiently controversial so as to essentially force the press to run with it.

Back to the post and its effect on Trump’s approval rating.  There must be a point at which insane rants like these are more sneered at and rejected by American voters than they are appreciated.  We’re angry, and we’re clearly not too bright, but again, there must be a point which these tactics fail to achieve its objectives.