He represented the Beauce-Nord district at the National Assembly of Quebec until 2012 as a member of the Coalition Avenir Québec.
He was also an administrator for the Union des producteurs agricoles (UPA), the vice-president of Régie Intermunicipale Beauce, the president of the CLSC Beauce-Centre and an administrator for the Saint-Jules Chamber of Commerce Grondin was first elected as a Member of the National Assembly in the 2003 election, with 46% of the vote.
In 2006, Grondin claimed that an influential Liberal supporter tried to convince him not to run in the 2007 election in order to favour the election of Liberal candidate Claude Drouin.
Grondin claims that a well paid job in the public service, which he declined, was offered to him.
Liberal leader and Premier of Quebec Jean Charest denied the accusation and dared Grondin to tell the public who made the offer.