Lots of Canadian PM's have won two (or more) consecutive majority govenments, besides Mulroney.
Sir John A MacDonald won two majorities in a row, then was defeated. Came back to win three in a row.
Laurier won 4 majorities in a row.
Mackenzie King won 3 majorities in a row.
St Laurent won two consecutive majority govenments.
Cretien's Liberals have won 3 consecutive majorities, and are gearing up for a possible fourth this spring, under the leadership of Paul Martin.