Canada's Prime Minister Justin Trudeau speaks at the Liberal national caucus holiday party in Ottawa The Trudeau government aims to let in 465,000 immigrants next year, despite serious shortages in housing and health care. As a percentage of the population, this is higher than most other developed nations and comes at a time when the country faces mounting debt and is likely headed into a recession. This demographic push began at a weekend gathering in 2011 in Muskoka, Ont., led by Dominic Barton, who served as global managing director of McKinsey & Company before becoming Canada’s ambassador to China for…