A few comments:
1. Whatever one’s disagreements with Justice Stevens’s jurisprudence may be, he served the country with dedication in a number of roles, and deserves our gratitude.
2. A great many people are going to write lamentingly about the fact that the Court, and the Republican party, have drifted to the Right in the time that John Paul Stevens has been on the Court. These people, interestingly enough, have an ideological antipathy towards the Right.
3. A great many people are going to write lamentingly about the possibility that Barack Obama’s next Supreme Court pick might be filibustered. These people, interestingly enough, will conveniently forget that scores of Democrats–including then-Senators Obama, Biden, and Clinton–sought to filibuster the nomination of Justice Alito.
4. Justice Stevens’s retirement actually makes things rather interesting on the Court in terms of the gamesmanship between the Justices. The most senior Associate Justice will now be Justice Scalia, but he is not likely to exercise often the senior Associate Justice’s power to assign opinions in cases in which the senior Associate Justice does not vote with the Chief Justice, given that Justice Scalia often does vote with the Chief. The next senior Associate Justice will be Justice Kennedy, who is the swing vote, but who is moderately conservative. He often votes with the conservative bloc, but on occasion, he votes on the other side. Even if he votes on the other side, however, Justice Kennedy’s non-liberal instincts will likely cause him to assign the opinion–whether the opinion will be a majority one, or a dissenting one–in a way that will not give voice to full-throated liberal views concerning the case at hand. As a consequence, many opinions going against the conservative bloc will likely be narrowly drawn; indeed, Justice Kennedy may assign a large number of those opinions to himself in order to keep Justices Breyer, Ginsburg, Soromayor, and the next Justice from writing opinions whose range and scope Justice Kennedy would not agree with.
This will likely have significant consequences for the jurisprudence of the Court’s liberal bloc. Majority opinions obviously shape the law, but so do dissenting opinions that pack a powerful philosophical punch. We certainly saw that as the case on the liberal side when Justice Stevens, a canny political operator, assigned opinions in the many cases in which he found himself going against the Chief Justice, and the rest of the conservative bloc. But with Justice Kennedy playing the role of senior Associate Justice in cases when he votes against the conservative bloc, opinions from the non-conservative side will probably lack powerful liberal sentiments, because Justice Kennedy, a non-liberal, will work to shape the opinion’s content via his power of assignment.
UPDATE: I see that Lyle Denniston is thinking the same thing that I am:
If the Chief Justice is in the majority when the Court divides, the Chief always has the assigning function, because, however long in the job of Chief Justice, that member of the Court always has top seniority. Only if the Chief Justice is not in the majority does the assigning task then fall to the Justice next highest in seniority. That has been Justice Stevens, for 16 years of his 34 years on the Court.
But Kennedy is moving up only a single notch in seniority. He is still outranked in seniority by Justice Antonin Scalia. So, if the Court’s eight other Justices were to split along conservative and liberal lines, and the four most likely conservative Justices attracted Kennedy’s vote, the assigning task would fall to the Chief Justice. In any divided Court with Kennedy and Scalia on the same side, Scalia would always be the assigning Justice should the Chief Justice not be on that side.
But, if Kennedy were to line up, in a divided case, with the Court’s four moderate-to-liberal Justices (assuming Stevens’ replacement sides with that bloc), Kennedy would always have the assigning task, inheriting it from Stevens. He would outrank, in seniority, all of the Justices in that bloc. He thus will be able to shape even the Court’s more liberally inclined outcomes, by the way he chooses the opinion authors. And, if he thought any of the other four might use an assignment to write an opinion more sweeping than he would want, he could assign the task to himself, and keep it within whatever bounds he chose so long as it did not drive off one of the four other votes he would need to keep a majority.
I should note that Denniston also believes it is possible that Justice Kennedy might line up with the liberal bloc more often in order to be able to exercise the assigning power.