They know very well what they are doing. It’s just that their wealth isolates them from the consequences of it. They don’t care about healthcare, climate change, education, unemployment, because that’s for the 95% to worry about. They are rich enough to don’t give a fuck, and they feel safe doing so.
And that rather obviously describes someone who’s rather obviously mentally ill.
Specifically, they lack empathy and have little to no conscience, so have little to no concern for the harm their decisions might cause to others. Those are the hallmarks of both antisocial personality disorder and psychopathy.
This is the key, and it really is just that simple.
Their hateful and ignorant ideals simply don’t have enough support to win with any significant voter turnout.
They therefore have exactly two options - to modify their positions to appeal to more people, or to hold to their positions and try to manipulate and corrupt the system so that they can win in spite of the fact that a clear majority rightly find them to be noxious. And they’ve blatantly chosen the latter.