Being a racist is not about poor decision making unless you count coming out the closet as a racist as a bad decision, then I agree.Hatred is hatred. Whether it's Rosanne's misguided twets or Sarah Palin indirectly calling for Obama's lynching during the 2008 Presidential election. Laurie Metcalf siad it herself, Rosanne makes poor decisions when she goes off her meds.
When she's on her meds, she makes smart decisions like hiring Whitney Cummings to be the show runner of the reboot. Again, I don't believe that Rosanne is an outright racist.
You are not racist because you are Bi-Polar, meds don't make you stop being a racist and you don't have to think she is one. Thankfully most of the world knows differently.