Just search for "kill clarence thomas" on Twitter. There's tons of stuff there. A conservative source reported on it, but unfortunately did not bother to archive the tweets.
Interestingly, there was far less for "kill Sam Alito" and "kill samuel Alito" - even though he was the guy who wrote the actual opinion. They really, really hate Clarence Thomas.
But don’t black lives matter?
I doubt Thomas voted for biden so by definition he isn't black.