There's an additional constraint of acting negligently. If you're going 45 on a road where the speed limit is fifty and someone sprints out in front of your car, you won't be convicted of vehicular manslaughter (assuming obviously that you didn't have time to react).
Somehow I'm reading "within a few feet" as "six inches". IME bicycles are much narrower than automobiles. If it's safe to pass an automobile, it's safe to pass a cyclist while leaving at least eight feet.
If it's not safe to pass, don't pass.
This seems beside the point? Above you seemed to imply it is inherently challenging to pass a cyclist. That is only the case if one attempts to pass in inappropriate situations. Cyclists have at least as much right to the road as motorists have.
We talk so much in America about gun control, why not also car control?