MONTREAL—With polls suggesting a tightening race the main party leaders are hoping to get a boost from the first of their two schedule televised debates as they return to the campaign trail today. Liberal Leader Justin Trudeau will follow up last night’s French−language encounter with an announcement and press conference later this morning in Mississauga, Ont. Conservative Leader Erin O’Toole will make an announcement in Montreal before joining supporters at an event in North Vancouver, and NDP Leader Jagmeet Singh will make a platform announcement this morning in Quebec City. Four of the main party leaders went head to head Thursday night in Montreal in the first televised debate of the campaign, trading barbs over the COVID-19 pandemic, health care and systemic racism in Quebec, a key battleground in Canada’s 44th federal election. The French-language debate on TVA, one of the province’s most-watched networks, comes at the midpoint of the …