Kath, what you are missing with Sanders is that a difference in ideology is healthy for a party - Sanders brought other issues to the table that are obviously priorities for a large part of the Democratic membership.  Not to say Bernie is the answer, he is too far left for a lot of the Dem voters.  And the rest need to be vigilant that the Dem party does not follow the path of the GOP to extremist ends or it will wind up in the same nova meltdown.