My first guess would be this year's Supreme Court decision about the Voting Rights Act.

tetromino_ • today at 3:13 PM • 2 replies • view on HN

Almost immediately after the ruling, a number of Republican states immediately put forth redrawn maps breaking up majority black districts.

duskwuff • today at 3:46 PM

Another candidate would be the DOJ ending attempts at school desegregation:

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