Barack Obama’s movement in the direction of centrism via a series of prominent appointments has not gone unnoticed by the left, and Christopher Hayes, in the Nation, fires a warning shot across Obama’s bows.

There will be moments in the next four years when a principled fight will be required, and if there is an uneasiness rippling through the minds of some progressives, it arises from their doubts about just how willing Obama will be to fight those fights. When a friend of mine decided to run for office this year, someone suggested that he write down a list of positions he wouldn’t take, votes he wouldn’t cast, then put it in a safe and give someone the key. The idea was that by committing himself in writing to some basic skeletal list of principles, he’d be at least partially anchored against the slippery slope of compromise that so often leads elected officials to lose their way.

Does Obama have such a list? And if so, what’s on it?

Read the whole thing.

The Obama presidency cannot avoid all the ingredients for the perfect political storm. His nomination could only be achieved via the support of the democrat party’s activist extremist base, but once elected Obama’s freedom of action will inevitably be severely curtailed by the nation’s current circumstances, featuring economic crisis at home and war overseas, two situations in which the implementation of leftwing policy choices can only lead to full-scale disaster.

The leftwing base will not only have to endure seeing Hillary Clinton made Secretary of States and Robert Gates’s appointment as Defense Secretary renewed. Obama will have to agree to tax cuts to save the economy, and Obama will have to agree to increased military efforts to save the US from humiliation at the hands of Islamic extremism.

Sooner or later, one pragmatic policy decision flying in the face of leftwing ideology will prove to be one too many and will become the straw that breaks the camel’s back of the nutroots base’s tolerance and support. After that watershed event, the left will turn on Obama with just as much savagery as it did on Lyndon Johnson, and it will destroy his presidency.

Obama is in a no win situation. We just need to buckle our seatbelts, prepare for a wild ride, and have a candidate ready for 2012.