Like @TN Toffee said, it's because she is a Republican. if you think people voting for her is terrible just think about how close Roy fn Moore came to winning in Alabama.I keep randomly going back to read into Kelly Loeffler, what she says, her life, her personality etc. and, above and beyond any politician I've ever known about ever, I can't see one valid reason why any human with a functioning brain would vote for her.
She's the absolute worst in seemingly every single respect.