Many French-speaking Catholics resented the way the federal government of Sir John A. Macdonald had Riel hanged for treason.
Mercier proposed to create a broader coalition which would include Conservative dissidents as well as his Liberal base.
In the following days 50,000 people gathered in the Champ de Mars in Montreal to hear Mercier voice their support for Riel.
The party won a narrow majority of seats to the Legislative Assembly of Quebec in the 1886 provincial election and took office in January 1887.
It won a landslide victory in the 1890 election, doing poorly only in the Mauricie area where it was opposed by Ultramontan Catholic Bishop Louis-François Richer Laflèche.