I've argued that in so doing, he's diminished himself by forfeiting what I called the power of purity.
I've argued that in doing so, he may be reflecting his judgment that the correlation of forces in the American body politic is such that he would not so readily prevail in a contest of power and persuasion --before the American electorate-- as to be able to escape undamaged and still capable of creating all the other sorts of change that he wants for America.
Here's another way of looking at Obama's possible strategic thinking.
Obama sees the victory represented by the 2008 election as very fragile. He imagines that evil could take over the country again.
So he’s focusing on shoring up and protecting his power. His main way of doing this is to build trust with most of the American people. And this, in terms, he is seeking to accomplish by arranging to be seen over an extended period of time as the guy who steps forward and speaks convincingly about our problems and about the solutions he proposes to solve the problems.
He's seen by most of the American people as working positively.
Obama’s strategy against the Republicans: HE’S LETTING THEM BECOME IDENTIFIED WITH THE UGLINESS.
They keep on coming from an ugly place. Obama keeps acting the responsible gentleman with the open hand.
What this contrast means is this: The American people are being given a protracted experience of looking at Obama and liking what they see, and looking at the Republicans and seeing the ugliness there.
The repetition over time makes the lesson lasting. The Republicans are grinding the mask of ugliness ever deeper into the flesh of their image in the American consciousness. And Obama’s appeal is magnified by the contrast.
[And we ought not forget about the factor of race, and what that would imply if Obama were to take on the posture of someone who is fighting against another part of our body politic. Obama is seen as African-American, and the other part of the body politic that he would be confronting in battle is one which happens to be the heir to the slave power.
The dark power that Obama is refraining from confronting is the Bushite/Texas/imperialist/exploitative coalition that gave us the criminality of the Bush regime, and it is --at its core-- a white Southern cadre.]