Find me some case precedents that have altered the definition of the 15th Amendment. As it is written, the key factor is that the right to vote was denied or “abridged” due to race, color, or previous condition of servitude (slavery). I see not one example of that in any link you provided, therefore in my opinion there is nothing unconstitutional.
Also, you were the one who brought up the 15th Amendment in your first post, I am simply arguing that there’s no evidence of a violation of the amendment. Sure, there may have been other laws and Acts that may have been violated, but nothing in the Constitution.