@RickiTarr
What drives it?
A time-traveller would look for or be sent to accomplish the minimum deletion from the timeline.
The further back they can be sent, the smaller the deletion is, but the less certain it is that other factors would not replace whatever was deleted.
There are lots of #SF stories about time-travel in attempts to improve history.
The #Governator was in some of them.
@GreatDismal - William Gibson - had to rewrite the prelude to the #Jackpot #dystopia last time.