Obama and Bush Jr had approval ratings around 50 % when they won re election.Bush Sr had approval ratings in the 30's when he lost re election,so did Ford and Carter.
3 yrs out from election means absolutely nothing. It may not even matter at election time as people may not answer pollsters correctly anymore especially with regard to this president. Your analysis is simplistic. You know how the pieces move, but cannot see more than one move at a time.
Hoping that the approval ratings /polls no longer work is probably your best hope but polling averages being off 10 + points is not likely to happen
If the democrats are "energized" as you say, then why are the dem leaders in full, full panic about the lack of donations to the party right when the midyear elections are coming up?