What he should have done instead was disarm his opponents. If he had built initial policy proposals from the middle, he could have wooed the moderate flank of the Republican party, marginalized the conservatives, and alleviated the concerns of those gettable voters in the South and the Midwest. This is precisely what Bill Clinton did between 1995 and 2000, and it is what the President's promises of "post-partisanship" suggested.
Our system of government can only produce policy when geographically broad coalitions favor it. The Senate, more than any other institution, forces such breadth. Obama created breadth the wrong way. He watered down initially liberal legislation to prompt just enough moderate Democrats to sign on. Instead, he should have built policy from the center, then worked to pick up enough votes on either side. The left would have been disappointed, but the right would have been marginalized and, most importantly, Independent voters - who have abandoned the President in droves - might still be on board.