a. This case is really in effect two cases, one about partisan gerrymandering under the Constitution; the other about racial discrimination in districting under the Voting Rights Act. I have some preliminary analysis of the first; but none yet on the second.
b. With regard to partisan gerrymandering, the important news is that Justice Kennedy remains the swing vote and is still searching for a judicially manageable standard. It is also important that both Chief Justice Roberts and Justice Alito have deferred, for a future case, whether they believe that a judicially manageable standard exists to adjudicate constitutional claims of partisan gerrymandering.
c. Today's decision says only, in effect, that there is no particular constitutional problem with mid-decade redistricting; all redistricting plans, whenever they occur during the 10 years between census-taking, will need to be evaluated according to the same constitutional standard, if a judicially manageable one can be found.
d. It is significant, I think, that there was a five-vote opinion of the Court (part II.A of Kennedy's opinion) saying that claims of partisan gerrymandering are subject to judicial review; this signals to me that Justice Kennedy would like to find a judicially manageable standard; he just hasn't yet. There are other indications in his opinion to this same effect, but he is proceeding cautiously in this area, as he has in the past.
e. Any judicially manageable standard acceptable to Justice Kennedy would have to evaluate the partisan effects of a redistricting plan as well as the motivations for it.
f. As a practical matter, one thing to look for is whether legislatures now will aggressively take advantage of the opportunity to do mid-decade redistricting; if so, it may have a backlash effect in increasing Justice Kennedy's desire to find a constitutionally principled way to intervene to stop partisan manipulation of district boundaries.