Open this photo in gallery: Ontario Premier Doug Ford holds a press conference outling his response to the tariffs the U.S. has placed on Canada, at Queen's Park in Toronto on March 4.Nathan Denette/The Canadian Press Canadian premiers banned U.S. booze from their liquor-store shelves, barred American companies from government contacts and floated cutting off supplies of power, nickel, uranium or potash, calling U.S. President Donald Trump’s tariffs a betrayal of a long-time ally. Provincial leaders pulled the trigger on retaliation plans many of them had announced weeks ago – while expressing support for Ottawa’s move to push back with...