Sorry to burst everyone's bubbles around here, but by objective standards Obama has been a successful POTUS and a far more competent one than his predecessor. The primary such standard is the amount of legislation proposed/passed/implemented, a value that makes Obama far above average.
His foreign policy has been a success: his election instantly boosted world public opinion, which matters to the extent that it feeds into our soft power, or ability to influence others. His emphasis on multilateralism is sound and the operation in Libya to secure those oil resources for the world (no, democracy was not and almost never is the primary goal) was a stellar success that cost zero American lives and a mere $2 billion (we each payed a little over $6 for it). On the other hand his administration's emphasis on drone strikes and covert operations has won the war on terror: Al Qaeda has been genuinely ravaged and barely functions as an organization. Such operations included the personally-authorized killing of OBL, an important symbolic victory.
Things are more complex at home. Banking regulation was passed, which includes the Volcker Rule banning proprietary trading and other measures that are seemingly necessary to prevent another bailout, but nobody knows just how much regulation is optimal. Obama also stepped up and addressed the issue predecessors pussied out on, healthcare. The resultant legislation was a centrist plan (anyone who calls it 'socialist' has never been to Europe or examined their public policy) based on a conservative policy proposal that originated with the Heritage Foundation (a mandate to tackle the free riders that increase costs). That it may get struck down does not reflect on Obama as he has no control over SC deliberations to begin with. He can only be evaluated for his specific actions.
Finally, we come to the economy, which is what actually dtermines elections anyway. There is an extraordinary amount of confusion about this as certain posters think we live in a system where the POTUS wields magical powers that determine the course of the economy. The misunderstanding is reinforced by presidents who take credit for growth and pundits who blame/credit everything happening to a president. The fact is this: we live in a capitalist where private actors control productivity. Corporations invest and hire/fire according to their plans, households only spend according to their perceptions of wealth, and banks lend in response to demand. Presidents do not control any of these variables, and can at best moderately nudge them in one or another direction.
Even considering this, CBO estimates put the number of jobs saved by the stimulus in the hundreds of thousands. The subsequent recovery has been tepid and has disappointed Obama and everybody else. But the point is, if the economic variables are all controlled by exogenous factors outside the WH, how can we lump all of the blame against Obama all the same? There is no evidence at all that a Republican president would have done anything differently, especially not since the stimuls contains much Friedman-esque monetary policy as is (the continued actions of the Fed belie the notion that the stimulus has been purely Keynesian).
In short, Obama has been an above-average president and performed admirably given the inherent limitations on the office (the position just isn't as powerful as many make it out to be) and the simply unprecedented circumstances inherited. People focus on the POTUS as a convenient symbol for everything the USG is doing and everything happening in the economy; the position is a convenient beacon for love and hate with a human face, when the real causality is mostly reserved for faceless machines comprised of the decisions of millions of individual actors (the USG + markets). People ought to understand as such when evaluating a US president.