He was previously a Member of National Assembly of Quebec for the riding of Roberval in the Saguenay-Lac-Saint-Jean region, losing to Premier Philippe Couillard in the 2014 general election.

Trottier went to Université Laval where he received a bachelor's degree in political science and a certificate in college education.

He also did a master's degree in regional studies at the Université du Québec à Chicoutimi.

Trottier was a lecturer at the UQAC in sociology for 23 years and a teacher at CEGEP de Saint-Félicien in political science and sociology for 18 years.

He was also a member of the MRC Maria-Chapdelaine and the mayor of Péribonka from 2001 to 2005.