“86” means to get rid of. Assassination is a stretch, a big one.
It still means kill someone. 86 means 80 miles out and 6 feet deep. Its how the mob would get rid of people. Drive them out 80 miles into nowhere, make them dig their own grave, then beat them newrly to death and bury them alive!
That may be the etymology but the usual colloquial use has been to toss something away. At least that’s how I’ve seen it used most of my life.
None of this changes the fact that Whitmer is a toobinhead.