I also believe the polls and comparisons are of different animals. Nixon and Carter were disliked for what they done. I'd bet Obama's problem with the people is from what he didn't do. I feel people expected Obama a more hands on president. People feel he compromises too easily and has way too much blind trust in opponents good faith. People were unhappy he did not get personally involved with healthcare reform. People didn't want more of the same, they wanted the public option. Obama believes in the system ie congress getting it done while he simply waits for the bill to land on his desk. LBJ would have never governed as Obama has. People expected Obama to govern more aggressive. Not as a back seat passenger. As far as I see it, Obama only seems to get his blood pressure going when he is attacked personally. When his progressive ideals are attacked, Obama acts like oh-well.
That laid back attitude pisses people off. Especially liberals. Obama needs to learn a little LBJ ass kicking.