The Liberals have had internecine warfare now for a generation - from the time Turner and Chretien had their tangles, through Paul Martin's first run at the top job and after Chretien had pushed Turner out, on through the Martin/Chretien war and to now where there are three, maybe four, blocs within the party. All fighting for a throne of dubious value.
The current Grit leadership group(s) and roster of functionaries have never known a period of peace in their party. New Liberals (those under 60) expect to fight enemies within before they fight enemies on the outside.
For most of the past 23 years, since the end of the Trudeau era, the Liberals seldom have been an entirely happy bunch fully behind their leader. There was unity for the first five or six years of the Chrétien era, but then the Martinites became restless, then more restless, until their man finally left the cabinet, thereby making the split open and final.
And the sky didn't fall.