You can point out that Trump is a predator, and his idiot fans will say "Yeah, predators are tough and scary and cool! That's what we want in a president!"
You can point out that Trump is a con-man, and his idiot fans will say "Yeah, con-men are cunning and smart! That's what we want in a president!"
You can point out that Trump has had shady connections to criminals and money launderers for decades, and his idiot fans will say "Yeah, people like that know how to get things done! That's what we want in a president!"
You can point out that Trump is a serial adulterer and his idiot fans will say "Yeah, he knows what he wants out of life and he gets it! That's what we want in a president!"
You can point out that Trump is a bully, and his idiot fans will say "Yeah, it's about time this country had a bully for a president!"
The root problem here is not that Trump's fans are unaware of his flaws: it's that they don't think they're flaws. They don't think these traits are flaws because they have a VERY different idea of what makes a good president than you do.