Dahlia Lithwick -- who is popping up all over the place including on Colbert -- had an article recently on the jurisprudence of President Obama. This led me to write this:
From Audacity of Hope:
I have to side with Justice Breyer's view of the Constitution -- that it is not a static but rather a living document, and must be read in the context of an ever-changing world.
His respect in the "fidelity" of the Constitution reflects the views of Goodwin Liu, who he nominated for the Ninth Circuit. Liu offers the left a chance for a strong constitutional theorist to be on the courts, someone many might wish will wind up on the Supreme Court. Both place an important place in "deliberative democracy" to give meaning to the Constitution; to quote Obama:
in which all citizens are required to engage in a process of testing their ideals against an external reality, persuading others of their point of view, and building shifting alliances of consent. ... [O]ur individual and collective judgments are at once legitimate and highly fallible.
This suggests he has a pragmatic view of judging, judges guided by a Breyer "Active Liberty" (to cite his book) approach, which furthers deliberative democracy and certain basic freedoms found in the document. The concern for democracy can fit in with Obama's concern for a judge who applies the law with the eye of the average citizen, his concerns for "empathy" in that regard. [See here and here for discussion of how "mere background" is not the deciding factor there. Her elite status is not promising as much as someone else in that regard, but it is not disqualifying empathy-wise. Kagan's ability to relate well with conservatives is a sign in that department.]
Kagan's most cited work, a discussion (with approval) of how presidents in recent years have taken a more direct role in the administration of laws, cites Breyer with approval. This includes the possibility of something like a line item veto (struck down via an opinion by Stevens that Kagan felt was poorly reasoned, supported by Clinton) or other congressional/executive policies that some might think give too much power to the President (cf. Stevens joining Scalia in dissent and Breyer joining the plurality here).
But, that he trusts to fallible process, fallible enough that the courts should give them some discretion unless the Constitution in some fashion blocks the way. Of course, there are various areas where he thinks this occurs where others do not -- up to a point, for instance, abortion rights are protected by various provisions. For instance, it can be that it is a choice taken out of the democratic process or (the Ginsburg approach) necessary for equality inside it.
Even here, he has a more flexible view than some, probably less so than Stevens in various ways. Rehnquist was seen as an ideal for someone like Bush, so he was replaced by his law clerk, John Roberts. Stevens is only an ideal for Obama up to a point. Breyer is more his ideal, so we who want a Stevens were set up to be disappointed, instead getting a Kagan.