Probably the most liberal POTUS to serve in my lifetime. Sometimes I think Obama tries to go as Left as he can, while still remaining politically viable. He certainly, unlike Clinton, has done nothing to really upset his base, including doing nothing on entitlements, even though he won't increase taxes on the middle class to pay for it - just a 4% increase or so on those making over 250K, which gets you about one twelfth of the way to something that will pencil.
That Obamacare was the Heritage Foundation's alternative to Hillarycare, which was pushed by Clinton at the same point in his Presidency, kind of throws a wrench into the notion that he's not to the right of Bill Clinton.
Clinton came into office in the wake of the collapse of communism, the rise of the Washington consensus, and the peak of a neoliberal tsunami sweeping the globe. Obama came into office in the wake of the failure of all of that. In context, Obama's embrace of neoliberalism has been remarkable. Obama even refuses to raise taxes on the middle class, whereas Clinton and his predecessor H.W. Bush did.
For the notion that Obama hasn't upset his base, is laughable to anyone who followed liberal blogs in 2009 and 2010. For instance, look up the term "hippie punching."