Thanks for your post. For clarity - JFK won Illinois by under 10,000 votes out of over 2.3 million per side, 4.7 million cast. Under 0.2%. Neither one of us can claim to "know" what happened there.
For further clarity Nixon won his own home state by a narrower margin, 50.1%, than Kennedy's win in Texas, 50.5%. And he only did so after the absentee ballots were counted in California.
What you said, that Chicago can sway Illinois (and hence sway the US presidential election) is exactly the point. This is achievable. A bad guy can steal an election. (Although in 1960, Illinois alone would not have gotten Nixon the election. He still needed to pull another 20 or so electoral votes from JFK). .
Why are you not making the same argument in regards to California in the 1960 election? After all, it was super close and had been initially called for JFK. NIxon's power base was in SoCal, the most populous part of state. We all know that Nixon was not above playing dirty pool. So why no hand wringing over absentee ballots putting Nixon over the top? The answer is simple, it does not fit the narrative that has been put out all these years. If JFK has won California, Illinois would have been irrelevant. I'm guessing you were not even aware of either one of these facts. But then again neither one of us can claim to know what happened there. See, two can play that game.
Anyway, there need to be measures in place confirming that does not happen
Those measures already exist. When you have people with decades of experience running elections being hounded out of office, or have people running for Secretary of State buying into the 2020 election lies that where the real danger is. https://www.propublica.org/article/trum ... e-resigned