By early evening it was evident that a landslide was in the making. As Liberal Party faithful gathered to celebrate at Montreal's Centre Pierre Charbonneau, loudspeakers boomed What a Feeling, the stirring theme song from the movie Flashdance. Liberal Party Chief Robert Bourassa, 52, took the microphone and, speaking in French, hailed his party's triumph as "a great victory for Canada." Switching to English, he pledged to "give back to Quebec the prosperity we had 15 years ago."
Across town, at the election-night headquarters of the Parti Quebecois, which had swept to power in 1976 vowing to withdraw the predominantly French-...