He served in the National Assembly of Quebec from 2007 to 2008, representing Nicolet-Yamaska as a member of the Action démocratique du Québec (ADQ).
His criminal background was discovered by the media during the campaign and was reported in newspapers across Canada; he initially denied having a police record, but acknowledged the truth when presented with incontrovertible evidence.
ADQ leader Mario Dumont accused the media of conducting a "witch hunt" against Dorion, who he said had turned his life around several years earlier.
[5] The Quebec Liberal Party formed a minority government after the 2007 election, and the ADQ became the official opposition in the National Assembly.
[8] Dorion was personally defeated in 2008, finishing third against Parti Québécois candidate Jean-Martin Aussant amidst a provincial swing away from the ADQ.