Hillary's idea is to reduce the speed limit back to 55 mph (true).
I bought a hybrid so I could go 70 mph and still get better gas mileage. Why should I have to go 55 mph just because someone else bought a 70,000 pound car to drive themselves across the state and it only gets 20 mpg at 55, and much worse at 70?
I can get 50 mpg at 70 mph, and better if I follow too close to trucks going 75 mph.