Commentary Par XXXI 37-39

The phrase 'a people just and sane' is the third and last in a series of parallel pairs, with the parallelism inverted in the third term: good/bad, good/bad, bad/good.  See [Par XVI 152], where Florentines in 'the good old days' were portrayed in much more positive terms.  Now things have changed, and Florentines are those left behind in order for Dante to associate with such people as they once were, now found only in Heaven.