This might also be applied to Obama's presidency.
He is reaping the dividend of his hope campaign. The reality contrasts. So his achievements seem small, even though they are not entirely absent. The obstacles of the constitutional structure are the realities which matter.
He seemed to see this once. But it turns out he is a fairly conservative chap. And anyway, as Hari used to tell us, the constitution is designed to make change - and particularly change to the constitution itself - difficult.