He was elected to the National Assembly in a by-election as a Parti Québécois member on September 20, 2004 in riding of Gouin in the Montreal region.
Girard was involved in politics in his teens, notably on the Parti Québécois (PQ) Youth Association in the riding of La Prairie.
He later worked for several ministers, including François Legault, André Boisclair and Sylvain Simard as a press secretary.
In the candidate selection process, he was backed by Pauline Marois and defeated high-profile Bloc Québécois vice-president, Dominique Ollivier, who was supported by Bernard Bigras, Gilles Duceppe and Louise Harel.
Early after his election, he left Marois' organization to back Bernard Landry who was gaining support in order to get a decent confidence score at a mandatory PQ internal vote.
In 2005, Bernard Landry resigned after gaining only 75% of his party support, Girard then convinced André Boisclair to make a bid for the PQ leadership, which he won.
His electoral office was occupied by FRAPRU, a social lobby supporting more public funded housing, police were forced to evacuate the illegal protesters.