Liberal leader Justin Trudeau launched the federal election campaign on Wednesday after asking the Governor General to dissolve parliament. Before the writ dropped, the Globe and Mail reported that the RCMP's investigation into potential obstruction of justice in the SNC-Lavalin affair has been hampered by the federal government's refusal to lift cabinet confidentiality. As Mercedes Stephenson reports, though Trudeau is urging Canadians to 'choose forward,' he'll face plenty of tough questions about his past on the campaign trail.