Obama did not do a U-turn. It is the worst naivete to think that what happened was "he had big ideas and he changed his mind." He had to bring up big ideas to get elected, and then he got elected the first Black president and some of you seem entirely too dense to actually grasp what that means. President. Not King.
Subject to all of those checks and balances you hear about and then some.
You people act as if he could wave a wand and just sweep away everyone and everything who was against his big ideas, when the opposite was at play.
Please, grow a better sense of politics.