Who the hell keeps electing her? Do those people like being the laughingstock of the country?
It's two different processes at work.
1. Some of her constituency is actually as dumb/ignorant as she is.
2. Some of her constituency knows what a train-wreck she is, and likes electing her as sort of a protest-vote to thumb their nose at "white America" who is repressing them etc.
Back when Marion Barry was getting re-elected as mayor of D.C. even after winding up on FBI video tape doing crack with a hooker, I had some people who had "feet in both worlds" so to speak explain this to me.