Agriculture is so mechanized at this point, that a serious cut in gasoline supplies could make it impossible for farmers to plant and bring in their crops. We're talking about a situation in which their could be an absolute shortage of food where even with rationing there isn't enough to both maintain exports and feed the US population.  

Electric tractors seem like a no brainer.  You have no distribution network issues, because you don't have to worry about finding a station to plug in at. And while you're at it you can switch over rural households to electric heat so you can preserve natural gas production for use in making fertilizer.

And I'll give my consent to any government that does not deny a man a living wage-Billy Bragg