By Dan Ralph -CP-It’s been a decades-long tradition in North America, but a Canadian professor of sport management says it might be time to re-examine the legitimacy of national anthems being played before games. Last weekend, sports fans in Canada voiced their displeasure with U.S. President Donald Trump’s announcement he was raising tariffs on Canadian and Mexican imports by 25 per cent. In hockey and basketball arenas across the country, they roundly booed the American national anthem before games. On Monday, Trump agreed to pause the tariffs for one month. That night, Nashville, Tenn., fans returned the favour before the Predators lost to Ottawa 5-2. On Tuesday, boos continued before NHL games in Vancouver and Winnipeg as well as Toronto’s Scotiabank Arena before the Raptors-New York Knicks contest. The spectator…