Sometimes I think they actively want to depopulate the southern states to reduce the amount of poor / black people. Rolling back federal assistance achieves that aim.
I've also heard that if you tell southerners that a law is applied in a discriminatory manner (unfairly targets blacks) then they actually like the law more than before. I think this is closely tied to the "Just World Fallacy", which you can read about and is extremely irrational, but a widespread phenomena. In that, people rationalize that those suffering bad effects must have deserved it. It is probably a psychological self-defence mechanism, because then you can rationalize that "it can't happen to me". It is also quite close to the way conservatives frame issues, and the opposite of how liberals do.
So, in other words, pointing out how outcomes are "unfair" plays to liberals worldview but plays against conservatives worldview. And you have to be very aware of how you frame issues. One of the Kentucky videos showed a poor black woman who can't get medical insurance, and how unfair and illogical it is. But this only reinforces the conservative / Just World belief system. If you want to break through that you need to frame the issue completely differently. Find a black woman who is a devout christian but can't get medical insurance. That would focus on the points of commonality between the conservatives and the person in the video. Because if it can happen to one christian it can happen to you, too.