It is mostly about the H1-B and entrepreneurial immigrants.
The Latinos will of course be the majority but they don't have the money to fund election wins. In two generall election cycles they will have the votes to win elections.
Then we have the Eastern Europeans.
What PBO has done is he has driven a wedge between the Republican pragmatists and the reactionaries. He knew that not having Congress in the next session, he might of well win points now and possibly win points when Congress attack him in the hearings and voting.
I'd disagree with all three of your points (and explain why, if I thought it would do any good) but it's easier just to point out he's become mostly irrelevant.
Not entrenched bipartisan law, since he ain't got enough homies to do much of anything except petulant payback.
