Projecting past trends to the future is full of speculative assumptions. One of which is that the president has no plan to elevate his approval rating by campaigning as the time gets closer.
He can certainly try, but the deck will be stacked against him with these variables, if in place:
further decay of US military position in nation-building exercise in Iraq/continued US media harping and melodrama/American impatience, short-termed vision and only supporting quick, short term dramatic victories, not long-drawn out commitments