I'm thinking in terms of raw power here, with a capital P, as a subject independent of politics. I'm thinking about what Power actually is, abstractly and practically. Machiavelli did this centuries ago, but the memes he used are no longer applicable.
I define capital P Power as simply the ready ability to influence large masses of people to get things done. There are various ways to attain it.
Money is of course, a way to Power. If you can amass enough capital, you will be granted a seat at the table of Power, should you choose to take it. Enormous concentrations of wealth (of which there are many in our young 21st Century) can determine and influence events in ways that any government might envy.
Holding political office plays a part in wielding Power, but not usually a major part. A President or a Senator or a mayor can often find ways to either help or hinder various Power players, and so become Powerful him/herself. But on the average, politicians serve as brokers to Power. They do not establish it.
Military establishments maintain rigid control over vast stores of men and materiel, and they are tightly bound to a network of arms manufactures - often more so than they are bound to the governments they putatively serve.
Religion is another avenue to Power. To hold sway over the hearts and minds of enough of the faithful, is to transcend reality itself. Religion has the ability to drive millions of people stark raving mad, or to lull them into acquiescence.
Corporate collusion is arguably the most Powerful force in the world today. It's more than just the sheer volume of money that behemoth corporations manage. It is rather that collectively they consistently and aggressively (and very effectively) advocate for the elimination of any governmental controls to their acquisition of yet more Power. Ideally they would reduce all government to the role of administration.
I am wondering whether I should put my favorite kind of Power here, in such august and time-honored company. I think I shall. There is, most assuredly in the world a kind of human solidarity, or perhaps human empathy, a certainty that we are all brothers and sisters when we meet face to face. I think this is nearly a universal human sentiment, in spite of the fact that the afore-mentioned loci of Power are ever present. As human beings, we naturally want to bond with other humans if we can, no matter what their race or nationality. Many things stand in the way of this, but it always seems to pop up like new shoots of grass, whenever the opportunity occurs. I believe in this kind of Power wholeheartedly.
When judging the performance of President Obama, it would behoove us as liberals to be cognizant of what Power actually is. Power is not grasped simply by electoral victory. Neither is it assumed automatically upon achieving office. Power is the ability to get things done, that's all it is. When Obama took office, he had very little of that. He had ten cards in a deck of 52, he was a rookie, and he was black. He has done well, so far.