Personally, I think it would be in the news for a couple days and then most Americans would pretty much forget about it and move on. Some folks on the left would point out this is further proof we need to abolish the CIA. The US Senate responds by a 98-2 vote to increase funding for the CIA, because white suburbanites are now scared the CIA will be eliminated and brown people will start bombing their big box stores.
If they were honest about the entire operation it would be pretty catastrophic. The people who did the killing itself would be dead by now, but not their immediate collaborators in what I guess you would call the coup government.
There's just so much stuff down that rabbit hole. It would re-frame the last 100 years of American history as something akin to crypto monarchy.