Cote was an active member of the Parti Québécois since 1970 as he was a member of the executive council, the treasurer, the legal adviser and the vice-president and president of the party for the Dubuc riding. He was also part of the YES committee for the 1980 Quebec referendum on sovereignty. He was also involved in the economic development of the La Baie region in Saguenay-Lac-Saint-Jean, and the regional board of the Caisses Desjardins.