This is just bizarre... I don't know if this is a hoax or what, but this is what I gathered:
John Hinckley Sr. had business dealings with George Bush Sr. (Bush Sr's company saved Hinckley's company in the 60s).
Scott Hinckley (John Hinckley's brother) was friends with Neil Bush, and was supposed to dine with him a day after the assassination attempt.
John Hinckley lived in Midland, TX at the same time when George W. Bush lived there. George W. Bush is quoted as saying he might have met him.
The Hinckleys were big supporters of the Bush family and donated to their various campaigns (including 1980 when George Bush Sr. ran against Reagan).
Of course, if the assassination attempt on Reagan had succeeded, G.W. Bush would've become president 8 years ahead of schedule.
I found a few interesting articles about this, but I'm not sure how credible those are... here's a samping:
http://www.rense.com/general45/hink.htm
http://www.whitehouse.org/news/2004/033004.asp (I know this is a parody site, but they have newspaper scans that look authentic).
Is this total bullshit, or another weird story about the interesting people the Bushes just happen to know?