From The Atlantic:

https://www.theatlantic.com/magazine/archive/2018/11/was-gary-hart-set-up/570802/

I found this to be fascinating for the following reason:

"If history had gone in a different direction in 1987, and Hart had become the 41st president rather than Bush, then Bill Clinton would not have had his chance in 1992, or perhaps ever. George W. Bush, who found his footing with a place on his father’s winning campaign, would probably never have emerged as a contender. When and whether Barack Obama and Donald Trump might ever have come onto the stage no one can say. “No first Bush if things had turned out differently,” Gary Hart told me. “Which means no second Bush—at least not when he arrived. Then no Iraq War. No Cheney. Who knows what else?”