These states may have started with extremely high murder rates. It's the growth in rates that would show whether OP is right or not, and those states with rapidly growing murders are not in the deep south.
(That said, none of the red states with high growth strike me as particularly likely to have liberal local DAs either, so I also question their argument.)
Expanding this to causation - that black people cause more crime - is not only a complete misuse of statistics - nothing there shows correlation, much less causation - it is an old racist saw. For example, a society which relegates people based on their skin color to poverty, lack of access to jobs, education, and healthcare, and continual discrimination, might be the causal agent. It could be that people in poverty, with poor educations, and difficult employment, are correlated with crime (but we'd need to look that up).
> Many of those red states have very liberal DAs who are refusing to prosecute certain crimes, asking for extremely low bail, and pursuing very short prison sentences, while also aggressively prosecuting alleged police misconduct.
Those DA's seem less prevelant in red states - is there some correlation there? And do you have evidence that these things increase crime rates? Most of the research says otherwise, the opposite practices had little impact for many years, and the people most affected by crime vote for these DAs.
It sounds like you're taking the article to mean "voting Republican is causal to murder", and are rebutting with "being black is causal to murder" (but are using a corollary fact to imply it). However, the first statement isn't being made by the article, and your implied rebuttal is neither verifiable nor does it even rebut the first statement, were the article making it. It's also unnecessarily provocative (unnecessary due to its irrelevance as described above). Of course this is all assumption you've forced me to make. By itself, the sentence you wrote doesn't say anything directly - you haven't connected it to the article explicitly.
Your second paragraph has the same problem, but the implication is more obvious: You believe the properties you've listed cause high murder rates. That doesn't seem to be true, though - can you either elaborate subjectively, or provide some other writeup that points to that conclusion?
then proceeds to tell OP that they're brainwashed. You were deliberately trying to offend, let's not mince words ok?
Your comment also seems to assume that the states which vote blue somehow don't have locally elected DA's? That doesn't explain why Missouri (with much less urbanization) has a higher murder than Illinois or Michigan (with "out--of-control" cities like Chicago and Detroit.