When it comes to social welfare, programs for the poor, healthcare, economic policies and general politics, I think Obama is a bit left of center and compares favorably with Lyndon Johnson and FDR.
When it comes to matters of government covert action and secrecy, citizens' privacy, leaks, whistle-blowers, national security matters conducted in the shadows, constitutional abuse in the name of public safety, etc., I believe Obama is a paranoid extremist and compares well with Hitler and Stalin.
I acknowledge the possibility that the problem is not so much Obama as it is an Orwellian national security / police-state mentality run amok, and Obama is simply the guy who's sitting at the head of the run-away train. But it's also possible that he is personally responsible for stoking the engines, determining the direction, and blowing the whistle (which of course is a silent whistle, because it's classified...).
Remember the good old days (before Reagan, before GW Bush) when the President was expected to obey the law? Or were those days just an illusion also, and our presidents have always felt themselves to be above the law?