Everybody has a theory on who Obama is, what he's doing, where he truly stands on issues, etc. Obama is awful and great and brilliant and passive. Of course President Obama is really, like almost everyone else, many things at many times. But I still thing it is pretty clear why he operates the way he does and why it befuddles so many of us.
George W Bush, Bill Clinton, Ronald Reagan, Jimmy Carter. What did all these former Presidents have in common that Obama does not have?
They were all Governors.
Meanwhile Obama cut his teeth as a legislator, both as an Illinois State Senator and US Senator from Illinois. So he comes from a deliberative background, he worked directly with those folks he is now negotiating with. Imagine all the private conversations that have taken place, the negotiations, the tough bargaining, the deal making and the simple comradeship that was made with those folks who may be his political opposites, but certainly share the idiosyncratic life that comes with being a legislator experience, which makes them in many ways kinsman (and women).
Marry that with the fact that Obama was Senator while W was President and his experience was that the Presidency was to adversarial to the legislature and tried too much to push the agenda. Obama believes far more in this deliberative process than the former Presidents who were Governors did. As Governors they saw their role differently than Obama, as being out front on things, on being less deferential to the legislative bodies and seeing themselves as a Check and Balance and not a partner.
This is clear with Obama in his desire to let Stimulus come from the Congress, DADT come from the Congress, DOMA come from the Congress. While he makes his positions known, he ultimately wants the legislature to do the heavy lifting. Why? Because he respects the institution, knows its processes and trusts them. It is clear when he says he will not invoke the 14th Amendment or he will not discontinue DADT by Executive Order. It has far more to do with his thoughts about the power of the Executive vis a vis the legislature than anything else. He will not use the Presidency to erode the power of the Congress in any way.
While this is not de facto good or bad, there are times when letting the legislature do the heavy lifting and the deliberation is needed. there are times when Obama has to be more in front of an issue and less conciliatory. Unfortunately, in my opinion (just my opinion, of course) he relies to heavily on the former and not enough on the latter.
Anyway, this is my theory.