I suspect the reality goes more like, farmers defended their water rights with absolutely rabid ferocity, and it was utter political suicide until now to make a

I suspect the reality goes more like, farmers defended their water rights with absolutely rabid ferocity, and it was utter political suicide until now to make any cuts or regulation at all. The agrilobby is incredibly powerful, and lobbies are famously uncompromising even to the point of working against their own best interests. Hell, it might still wind up ruining several political careers.