Plurity usually deals more with the particular case at hand where as the concurrent opinion is a more general note but still in support of the plurity decision. Scalia said more than just ruling on this case, it should not only be upheld but SCOTUS (and apellete courts in general) should refrain from involving itself in local election law. His argument is based in that constituionally we are a republic, effectively now a democracy, but regardless we have never been a jurisocracy. Lemmey  talk